This work was supported by NHLBI K01 HL155241 and AHA CDA849387 awarded to the author P.C.R.

<ol>
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M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Targeted+therapy+of+pulmonary+arterial+hypertension:+Updated+recommendations+from+the+Cologne+Consensus+Conference+2018.">Targeted therapy of pulmonary arterial hypertension: Updated recommendations from the Cologne Consensus Conference 2018.</a> International Journal of Cardiology. 272, 37-45 (2018).</li><li>Sommer, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+and+future+treatments+of+pulmonary+arterial+hypertension.">Current and future treatments of pulmonary arterial hypertension.</a> British Journal of Pharmacology. 178 (1), 6-30 (2021).</li><li>Farber, H. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Five-year+outcomes+of+patients+enrolled+in+the+REVEAL+registry.">Five-year outcomes of patients enrolled in the REVEAL registry.</a> Chest. 148 (4), 1043-1054 (2015).</li><li>Zolty, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+experimental+therapies+for+treatment+of+pulmonary+arterial+hypertension.">Novel experimental therapies for treatment of pulmonary arterial hypertension.</a> Journal of Experimental Pharmacology. 13, 817-857 (2021).</li><li>Jasmin, J. F., Lucas, M., Cernacek, P., Dupuis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effectiveness+of+a+nonselective+ET(A/B)+and+a+selective+ET(A)+antagonist+in+rats+with+monocrotaline-induced+pulmonary+hypertension.">Effectiveness of a nonselective ET(A/B) and a selective ET(A) antagonist in rats with monocrotaline-induced pulmonary hypertension.</a> Circulation. 103 (2), 314-318 (2001).</li><li>Stenmark, K. R., Meyrick, B., Galie, N., Mooi, W. J., McMurtry, I. 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F., Ryan, T., Feigenbaum, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Feigenbaum's echocardiography. 7th edn. , (2010).</li><li>Kimura, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+right+ventricle+by+speckle+tracking+and+conventional+echocardiography+in+rats+with+right+ventricular+heart+failure.">Evaluation of right ventricle by speckle tracking and conventional echocardiography in rats with right ventricular heart failure.</a> International Heart Journal. 56 (3), 349-353 (2015).</li><li>Cheng, H. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+right+ventricular+structure+and+function+in+mouse+model+of+pulmonary+artery+constriction+by+transthoracic+echocardiography.">Assessment of right ventricular structure and function in mouse model of pulmonary artery constriction by transthoracic echocardiography.</a> Journal of Visualized Experiments. 84, e51041 (2014).</li><li>Mazurek, J. A., Vaidya, A., Mathai, S. C., Roberts, J. D., Forfia, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Follow-up+tricuspid+annular+plane+systolic+excursion+predicts+survival+in+pulmonary+arterial+hypertension.">Follow-up tricuspid annular plane systolic excursion predicts survival in pulmonary arterial hypertension.</a> Pulmonary Circulation. 7 (2), 361-371 (2017).</li><li>Grapsa, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+and+hemodynamic+predictors+of+survival+in+precapillary+pulmonary+hypertension:+seven-year+follow-up.">Echocardiographic and hemodynamic predictors of survival in precapillary pulmonary hypertension: seven-year follow-up.</a> Circulation: Cardiovascular Imaging. 8 (6), 002107 (2015).</li><li>Bernardo, I., Wong, J., Wlodek, M. 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The authors have nothing to disclose.

Echocardiographic evaluation of the RV is a valuable discovery tool for the screening of the effectiveness of novel treatments in animal models of PAH. In-depth characterization of the RV structure and function is necessary as novel targets in treating PAH address RV remodeling4,14. This study describes a detailed protocol that allows for the successful characterization of RV structure and function.
The complex structural geometry and positioning behind the sternum make echocardiographic characterization of the RV difficult; thus, modified echocardiographic views are used to facilitate RV visualization and to assist in precise identification of the RV endocardial borders during analyses. In this regard, modified PLAX is used for better visualization and to obtain the pulmonary flow velocities and morphological measurements of the RV. Other protocols have described the use of parasternal short-axis views to measure pulmonary flow and RV wall thickness15; however, the use of modified PLAX allows consistent representative views of the pulmonary flow velocities to be obtained, and also improves the RV free wall definition. Additionally, the RV focused four-chamber apical view is used to improve the visualization of the RA and RV chamber walls and consistently obtain measurements of the RV systolic and diastolic parameters. 
The following parameters are recommended to assess RV systolic function: TAPSE, RVFAC, RIMP, and S'. TAPSE is a measurement of RV longitudinal contraction and has been reported to correlate with the degree of RV dysfunction16; however, TAPSE only evaluates longitudinal contraction without taking into consideration the radial component of contraction that becomes relevant in a dilated RV11. Despite its limitation, TAPSE remains a routinely obtained parameter, as it is easier to acquire compared to RVFAC and RIMP; however, a full evaluation of the degree of systolic dysfunction should include the assessment of S', RIMP, and RVFAC. S' is easily measured, reliable, and reproducible, however it only evaluates longitudinal systolic function. In humans, RVFAC correlates well with RV ejection fraction (EF)10 and is a more accurate measurement of RV function than TAPSE. RIMP, defined as [TCO-ET]/ET, is an index of global RV performance, reflects both RV systolic and diastolic function, and is a prognostic marker in patients with PAH17. RIMP is measured from TV PW Doppler since it can be more easily obtained, although it can also be measured from the tissue Doppler of lateral tricuspid annulus. It is important to use several indices of RV systolic function when assessing the effectiveness of drug treatment in PAH animal models to overcome the limitation of each measurement. The use of the RVEF as a measurement of systolic function is not recommended due to the complexity of the RV geometry, which leads to grossly underestimated volumes10.
RV diastolic function in rats is an understudied area due to the technical difficulties in obtaining the TV flow velocities and the TV lateral annulus tissue Doppler. By using the RV focused four-chamber apical view as stated in this protocol, consistent echocardiographic views with good endocardial border definition can be obtained. E/E' ratio and RAA should be used as a measure of RV diastolic function in early RV dysfunction. Strain analysis has become a powerful tool to access LV systolic dysfunction at the initial stages of LV dysfunction; however, only a few studies use this type of analysis to evaluate the RV14,18, due to the difficulties encountered in visualizing the entire wall and in obtaining high-quality echocardiographic images that are necessary for strain analysis. Although strain analyses were not performed in this study, the quality of the images obtained following this protocol is sufficient to perform this type of analysis, if needed. 
Finally, this protocol provides a detailed description of the echocardiographic views necessary to assess RV and RA morphology, as well as to characterize RV systolic and diastolic function. These data provide an enhanced evaluation of the efficacy of novel compounds to disrupt PAH development in rodent animal models.

PAH is a progressive disease defined as a mean pulmonary arterial pressure at rest of greater than 20 mmHg1. Pathological changes in PAH include pulmonary artery (PA) remodeling, vasoconstriction, inflammation, and fibroblast activation and proliferation. These pathological changes lead to increased pulmonary vascular resistance and, consequently, right ventricular remodeling, hypertrophy, and failure2. PAH is a complex disease that involves crosstalk between several signaling pathways. The currently approved drugs for treating PAH mostly target vasodilator pathways, including the nitric oxide-cyclic guanosine monophosphate pathway, prostacyclin pathway, and endothelin pathway. Therapeutics targeting these pathways have been used as both monotherapies and in combination therapies3,4. Despite the advances in treatment for PAH in the last decade, findings from the US-based REVEAL registry show a poor 5 year survival rate for newly diagnosed patients5. More recently, emerging therapeutic modalities have focused on disease-modifying agents that can impact the multifactorial pathophysiology of the vascular remodeling occurring in PAH in the hope of disrupting the disease6.
Animal models of PAH are invaluable tools in assessing the efficacy of new drug treatments. The MCT-induced PAH rat model is a widely used animal model characterized by remodeling of the pulmonary arterial vessels, which in turn leads to increased pulmonary vascular resistance and right ventricular hypertrophy and dysfunction7,8. To assess the efficacy of new treatments, researchers normally focus on the terminal assessment of RV pressure without considering the longitudinal evaluation of PA pressure, RV morphology, and RV function. The use of noninvasive and non-terminal imaging techniques is crucial for a comprehensive examination of disease progression in animal models. Transthoracic echocardiography remains the standard approach to evaluating heart morphology and function in animal models due to its low cost and ease of use compared to other imaging modalities, such as magnetic resonance imaging. However, echocardiographic evaluation of the RV can be challenging due to the RV positioning beneath the sternum shadow, its well-developed trabeculation, and its anatomical shape, all of which make it difficult to delineate the endocardial border9,10,11.
This article aims to describe a comprehensive protocol to evaluate RV dimensions, areas and volumes, and systolic and diastolic function in naive and MCT-induced PAH in Sprague Dawley (SD) rats. Additionally, this protocol details a method to assess echocardiographic dimensions in the normal and dilated right atrium.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.9% sodium cloride injection USP</td>
			<td>Baxter</td>
			<td>2B1324</td>
			<td></td>
		</tr>
		<tr>
			<td>Braided cotton rolls</td>
			<td>4MD Medical Solutions</td>
			<td>RIHD201205</td>
			<td></td>
		</tr>
		<tr>
			<td>Depilating agent</td>
			<td>Wallgreens</td>
			<td>Nair Hair Remover&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>Electrode gel</td>
			<td>Parker Laboratories&#160;</td>
			<td>15-60</td>
			<td></td>
		</tr>
		<tr>
			<td>High frequency ultrasound image system and imaging station</td>
			<td>FUJIFILM VisualSonics, Inc.</td>
			<td>Vevo 2100</td>
			<td></td>
		</tr>
		<tr>
			<td>Isoflurane</td>
			<td>MedVet</td>
			<td>RXISO-250</td>
			<td></td>
		</tr>
		<tr>
			<td>Male sprague Dawley rats</td>
			<td>Charles River Laboratories</td>
			<td>CD 001</td>
			<td>CD IGS Rats (Crl:CD(SD))</td>
		</tr>
		<tr>
			<td>Monocrotaline (MCT)</td>
			<td>Sigma-Aldrich</td>
			<td>C2401</td>
			<td></td>
		</tr>
		<tr>
			<td>Rectal temperature probe &#160;</td>
			<td>Physitemp&#160;</td>
			<td>RET-3</td>
			<td></td>
		</tr>
		<tr>
			<td>Sealed induction chambers</td>
			<td>Scivena Scientific</td>
			<td>RES644&#160;</td>
			<td>3 L size</td>
		</tr>
		<tr>
			<td>Solid-state array ultrasound transducer</td>
			<td>FUJIFILM VisualSonics, Inc.</td>
			<td>Vevo MicroScan transducer MS250S</td>
			<td></td>
		</tr>
		<tr>
			<td>Stainless steel digital calipers</td>
			<td>VWR Digital Calipers</td>
			<td>62379-531</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrasound gel&#160;</td>
			<td>Parker Laboratories&#160;</td>
			<td>11-08</td>
			<td></td>
		</tr>
		<tr>
			<td>Vevo Lab software</td>
			<td>FUJIFILM VisualSonics, Inc.</td>
			<td></td>
			<td>Verison 5.5.1</td>
		</tr>
	</tbody>
</table>

comprehensive echocardiographic assessment of right ventricle function in a rat model of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a progressive disease caused by vasoconstriction and remodeling of the small arteries in the lungs. This remodeling leads to increased pulmonary vascular resistance, worsened right ventricular function, and premature death. Currently approved therapies for PAH largely target pulmonary vasodilator pathways; however, recent emerging therapeutic modalities are focused on other novel pathways involved in the pathogenesis of the disease, including right ventricle (RV) remodeling. Imaging techniques that allow longitudinal assessment of novel therapeutics are very useful for determining the efficacy of new drugs in preclinical studies. Noninvasive trans-thoracic echocardiography remains the standard approach to evaluating heart function and is widely used in rodent models. However, echocardiographic evaluation of the RV can be challenging due to its anatomical position and structure. In addition, standardized guidelines are lacking for echocardiography&#160;in preclinical rodent models, making it difficult to carry out a uniform assessment of RV&#160;function across studies in different laboratories. In preclinical studies, the monocrotaline (MCT) injury model in rats is widely used to evaluate drug efficacy for treating PAH. This protocol describes the echocardiographic evaluation of the RV in na&#239;ve and MCT-induced PAH rats.

In this study, MCT-treated rats were used as a model of PAH. Echocardiographic analysis was performed on Study Day 23 post-MCT administration, and all measurements and calculations represented averages from three consecutive cycles. Echocardiographic parameters obtained from control (vehicle: deionized water) and MCT-treated (60 mg/kg) rats are shown in Table 1.
Representative images of the PLAX view in control and MCT-treated rats are shown in Figure 1A. These images are used as an initial assessment of the position of the heart and LV morphology. Quantitative assessments of the RV are obtained in a modified PLAX view, because this allows visualization of the RV (Figure 1B). In the modified PLAX view, the MCT-treated rats show an enlarged right ventricle and the left ventricle appears displaced from its position when compared with the control rats (Figure 1B). M-mode is obtained in the modified PLAX view at the widest area of the RV and used to measure RVIDd, RVIDs, and RVFWT (Figure 1C). RVIDd, RVIDs, and RVFWT are measured, excluding trabeculation in the wall, and RVFWT is obtained at the peak of the R wave of the ECG. As expected, a significant increase in RVIDd, RVIDs, and RVFWT are observed in the MCT-treated rats (Figure 1C and Table 1), indicating RV dilation and thickening of the RV free wall.
Doppler imaging is used to measure PA flow velocities (Figure 2B). In control rats, pulmonary flow exhibits a symmetrical V shape, with a peak velocity that occurs in mid systole (Figure 2B, upper panel). In contrast, in MCT-treated rats, peak velocity is slower and happens earlier in systole, resulting in a significantly shortened PAT and smaller PAT/PET and PAT/CL ratios (Table 1). Additionally, MCT-treated rats exhibit a notch in late systole (Figure 2B,&#160;lower panel). PV PW Doppler is used to measure the PV VTI (Figure 2B); PV CO and PV SV are calculated using the PV VTI and PV diameter measurements, respectively. PV CO and PV SV are significantly lower in the MCT-treated rats (Table 1), indicating impaired systolic function. HR is obtained from the PV PW Doppler measurements and is comparable between the control and MCT-treated rats (Table 1).
The RV focused apical four-chamber view is used to measure RVEDA, RVESA, and RAA (Figure 3), and RVFAC is calculated from RVEDA and RVESA. As stated earlier, trabeculations in the wall, if present, must be excluded from these measurements. RVFAC is significantly decreased in MCT-treated rats (Table 1), suggesting RV systolic dysfunction. MCT-treated rats also exhibit RA dilation because of increased PA pressure (Figure 3A,B,&#160;right panels, and Table 1). In normal conditions, the LV cavity has a higher pressure than the RV, resulting in a septal curvature of the LV throughout the cardiac cycle (Figure 3A,B, left panels). When the RV pressure pathologically increases in PAH, this normal curvature is lost, and the interventricular septum appears &#34;flattened&#34;13, as shown in Figure 3A,B (right panels). The RV focused apical four-chamber view is also used to measure TAPSE from the M-mode interrogation of the tricuspid annulus (Figure 4). TAPSE is significantly reduced in MCT-treated rats (Figure 4B and Table 1), suggesting compromised RV function.
Diastolic function is assessed from the PW Doppler evaluation of the TV flow and lateral TV lateral annulus tissue Doppler. MCT-treated rats show a significantly higher E wave and RVMPI and a tendency toward an increased E/E&#39; ratio (Figure 5 and Table 1), suggestive of impaired diastolic function. The TV annulus tissue Doppler view is also used to measure E&#39; and S&#39; (Figure 6B). MCT-treated rats exhibit significantly slower S&#39;, confirming decreased RV systolic function (also demonstrated by a reduction in PV CO and PV SV). No significant change in E&#39; is observed in MCT-treated rats. A and A&#39; can also be obtained from the TV flow PW Doppler and lateral TV lateral annulus tissue Doppler, respectively. These parameters are not discussed in this article.
Cardiac tissue mass measurements at terminal harvest and echocardiographic analyses support RV hypertrophy in MCT-treated rats when compared to control rats. As shown in Table 2, Fulton Index and the RV/TL ratio are significantly increased in MCT-treated rats as compared to control rats. Additionally, MCT-treated rats show an increased LV+S/TL ratio, indicating LV hypertrophy. MCT-treated rats also exhibit an increased LW/TL ratio, suggesting pulmonary edema.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/63775/63775fig01.jpg" /> 
Figure 1: Parasternal long-axis (PLAX) views. (A) Representative images of conventional PLAX to visualize the left ventricular (LV) outflow, left atria (LA), right atria (RA), and aortic valve (AV) in a control rat (left panel) and monocrotaline (MCT)-treated rat (right panel). (B) Representative images of modified PLAX view to visualize the right ventricular (RV) outflow tract, the interventricular septum (IVS), the LV, and the AV in a control rat (left panel) and MCT-treated rat (right panel). In rats, the M-mode sample volume line is usually placed between the shadow of two contiguous vertebrae (shown with blue arrows). (C) Examples of M-mode measurements in a control rat (top panel) and MCT-treated rat (bottom panel). Measurements include RV free wall thickness (RVFWT), RV internal diameter during diastole (RVIDd), and RV internal diameter during systole (RVIDs). For easy viewing, the measurements of only one cardiac cycle are shown. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63775/63775fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/63775/63775fig02.jpg" /> 
Figure 2: PV diameter and pulmonary artery flow velocities. (A) Representative images of modified PLAX view to visualize the pulmonary artery and to measure the pulmonary valve (PV) diameter in a control rat (left panel) and monocrotaline (MCT)-treated rat (right panel). (B) Pulmonary ejection time (PET) is measured starting at the point of acceleration to the point of return to baseline in a control rat (top panel) and MCT-treated rat (bottom panel). Pulmonary acceleration time (PAT) is the time interval between the point of acceleration to the peak of velocity. Pulmonary valve peak systolic velocity (PV PSV) is measured at the peak of the Doppler flow. PV velocity time integral (PV VTI) is traced in blue using the software option. Cardiac cycle length (CL) is measured from the point of acceleration of one cycle to the point of acceleration of the next cycle. Late systole notching is observed in MCT-treated rats. Arrows indicate the three consecutive cycles that were considered for calculations. Representative measurements are shown in different cycles for easy viewing, but all measurements were taken in each of the three cycles. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63775/63775fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/63775/63775fig03.jpg" /> 
Figure 3: RV focused apical four-chamber view. (A) Representative images of the right ventricular end-systolic area (RVESA) and right atrial area (RAA) in a control rat (left panel) and monocrotaline (MCT)-treated rat (right panel). Upper panels show images without tracing, and lower panels show traced areas. Measurements were taken using ENDOarea;s and 2D area tools to calculate RVESA and RAA, respectively. (B) Sample images of right ventricle end-diastolic area (RVEDA) using the ENDOarea;d software tool in a control rat (left panel) and MCT-treated rat (right panel). Upper panels show images without tracing, and lower panels show traced areas. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63775/63775fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/63775/63775fig04.jpg" /> 
Figure 4: Tricuspid annular plane systolic excursion (TAPSE). (A) Upper panel: right ventricular focused apical four-chamber view in a control rat. Right ventricle (RV), right atria (RA), and tricuspid valve (TV) are visualized. Lower panel: M-mode interrogation of the tricuspid annulus to measure TAPSE in control rats. (B) Upper panel: right ventricular focused apical four-chamber view in a monocrotaline (MCT)-treated rat. Lower panel: M-mode interrogation of the tricuspid annulus to measure TAPSE in an MCT-treated rat. Arrows indicate the three consecutive measurements that were considered for calculations. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63775/63775fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/63775/63775fig05.jpg" /> 
Figure 5: Pulsed wave Doppler of tricuspid inflow. Example of pulsed Doppler recordings of tricuspid inflow to measure the blood inflow velocity across the tricuspid valve during early diastolic filling (E, in blue), late diastolic filling (A, in blue), tricuspid closure-open time (TCO), and ejection time (ET) in (A) a control rat and in (B) a monocrotaline (MCT)-treated rat. Arrows indicate the three consecutive cycles that were considered for calculations. Representative measurements are shown in one cycle for easy viewing, but all measurements were taken in each of the three cycles. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63775/63775fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/63775/63775fig06.jpg" /> 
Figure 6: Tissue Doppler of the lateral tricuspid annulus. Tissue Doppler sample images of peak systolic myocardial velocity at the lateral tricuspid annulus (S&#39;, in blue) and peak myocardial relaxation velocity at early diastole (E&#39;, in blue) and late diastole (A&#39;, in blue) in (A) a control rat and in (B) a monocrotaline (MCT)-treated rat. Arrows indicate the three consecutive cycles that were considered for calculations. Representative measurements are shown in one cycle for easy viewing, but all measurements were taken in each of the three cycles. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/63775/63775fig06large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td colspan="2" rowspan="3">Echocardiographic parameters</td>
			<td colspan="4">Experimental groups</td>
		</tr>
		<tr>
			<td colspan="2">Control (vehicle)</td>
			<td colspan="2">MCT (60 mg/kg)</td>
		</tr>
		<tr>
			<td>mean &#177; SD</td>
			<td>n</td>
			<td>mean &#177; SD</td>
			<td>n</td>
		</tr>
		<tr>
			<td colspan="2">Boby weight range (kg)</td>
			<td>0.352-0.431</td>
			<td>8</td>
			<td>0.231-0.296</td>
			<td>9</td>
		</tr>
		<tr>
			<td rowspan="7">Morphology</td>
			<td>RVIDd (mm)</td>
			<td>2.72 &#177; 0.43</td>
			<td>8</td>
			<td>5.04 &#177; 1.68*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>RVIDs (mm)</td>
			<td>1.77 &#177; 0.52</td>
			<td>8</td>
			<td>4.04 &#177; 1.58*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>RVFWT (mm)</td>
			<td>0.59 &#177; 0.13</td>
			<td>8</td>
			<td>1.38 &#177; 0.30*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PV diameter (mm)</td>
			<td>3.72 &#177; 0.38</td>
			<td>8</td>
			<td>3.50 &#177; 0.24</td>
			<td>9</td>
		</tr>
		<tr>
			<td>RAA (mm2)</td>
			<td>17.97 &#177; 3.14</td>
			<td>5</td>
			<td>34.46 &#177; 12.15*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>RVEDA (mm2)</td>
			<td>37.97 &#177; 6.57</td>
			<td>5</td>
			<td>52.78 &#177; 7.41*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>RVESA (mm2)</td>
			<td>21.68 &#177; 8.41</td>
			<td>5</td>
			<td>44.40 &#177; 5.04*</td>
			<td>8</td>
		</tr>
		<tr>
			<td rowspan="15">Systolic function</td>
			<td>RVFAC (%)</td>
			<td>44.16 &#177; 16.55</td>
			<td>5</td>
			<td>15.49 &#177; 5.07*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>PET (ms)</td>
			<td>70.78 &#177; 5.89</td>
			<td>8</td>
			<td>74.52 &#177; 7.65</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PAT (ms)</td>
			<td>32.56 &#177; 6.01</td>
			<td>8</td>
			<td>20.23 &#177; 4.21*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PAT/PET Ratio</td>
			<td>0.46 &#177; 0.10</td>
			<td>8</td>
			<td>0.27 &#177; 0.05*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PV PSV (mm/s)</td>
			<td>1032.35 &#177; 100.76</td>
			<td>8</td>
			<td>605.85 &#177; 170.29*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PVCO (mL/min)</td>
			<td>179.03 &#177; 39.92</td>
			<td>8</td>
			<td>73.04 &#177; 36.57*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PVSV (&#956;L)</td>
			<td>505.53 &#177; 114.04</td>
			<td>8</td>
			<td>215.97 &#177; 99.58*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>HR (bpm)</td>
			<td>358.52 &#177; 43.14</td>
			<td>8</td>
			<td>324.69 &#177; 42.35</td>
			<td>9</td>
		</tr>
		<tr>
			<td>CL (ms)</td>
			<td>169.86 &#177; 22.60</td>
			<td>8</td>
			<td>185.84 &#177; 22.56</td>
			<td>9</td>
		</tr>
		<tr>
			<td>PAT/CL Ratio</td>
			<td>0.20 &#177; 0.05</td>
			<td>8</td>
			<td>0.11 &#177; 0.02*</td>
			<td>9</td>
		</tr>
		<tr>
			<td>TAPSE (mm)</td>
			<td>3.33 &#177; 0.63</td>
			<td>7</td>
			<td>1.47 &#177; 0.49*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>ET (ms)</td>
			<td>77.83 &#177; 11.16</td>
			<td>7</td>
			<td>78.52 &#177; 7.82</td>
			<td>8</td>
		</tr>
		<tr>
			<td>TCO (ms)</td>
			<td>92.93 &#177; 9.58</td>
			<td>7</td>
			<td>107.96 &#177; 11.77*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>RVMPI&#160;</td>
			<td>0.20 &#177; 0.09</td>
			<td>7</td>
			<td>0.39 &#177; 0.19*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>S&#39; (mm/s)</td>
			<td>62.62 &#177; 12.78</td>
			<td>6</td>
			<td>25.90 &#177; 8.26*</td>
			<td>7</td>
		</tr>
		<tr>
			<td rowspan="3">Diastolic function</td>
			<td>E (mm/s)</td>
			<td>460.33 &#177; 82.90</td>
			<td>7</td>
			<td>684.89 &#177; 177.53*</td>
			<td>8</td>
		</tr>
		<tr>
			<td>E&#39; (mm/s)</td>
			<td>53.07 &#177; 26.35</td>
			<td>6</td>
			<td>40.82 &#177; 23.34</td>
			<td>7</td>
		</tr>
		<tr>
			<td>E/E&#39;&#160;</td>
			<td>9.79 &#177; 3.18</td>
			<td>6</td>
			<td>23.79 &#177; 17.34</td>
			<td>7</td>
		</tr>
	</tbody>
</table>
Table 1: Right ventricle echocardiographic parameters at Day 24 post-MCT (MCT Group) or vehicle (Control Group) administration in Sprague Dawley rats. Data presented as mean &#177; SD. Student&#39;s t-test was used to analyze data. *p &#60; 0.05. Abbreviations: Monocrotaline (MCT), RV internal diameter during diastole (RVIDd), RV internal diameter during systole (RVIDs), RV free wall thickness (RVFWT), right atrial area (RAA), right ventricle end-diastolic area (RVEDA), right ventricular end-systolic area (RVESA), RV fractional area change (RVFAC), pulmonary ejection time (PET), pulmonary acceleration time (PAT), pulmonary peak systolic velocity (PV PSV), cardiac output (PV CO), stroke volume (PV SV), heart rate (HR), cardiac cycle length (CL), tricuspid annular plane systolic excursion (TAPSE), ejection time (ET), tricuspid closure open time (TCO), RV myocardial performance index (RVMPI), tricuspid annular velocity at systole (S&#39;), velocity of blood flow across the TV during early diastolic filling (E), and tricuspid annular velocity at early diastole (E&#39;).
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td rowspan="2">Necropsy parameters</td>
			<td colspan="2">Experimental groups</td>
		</tr>
		<tr>
			<td>Control 
			(Vehicle, n = 6-8)</td>
			<td>MCT 
			(60 mg/kg, n = 7-9)</td>
		</tr>
		<tr>
			<td>HW/TL (mg/mm)</td>
			<td>29.4 &#177; 2.40</td>
			<td>30.8 &#177; 3.22</td>
		</tr>
		<tr>
			<td>LW/TL (mg/mm)</td>
			<td>40.3 &#177; 2.03</td>
			<td>55.8 &#177; 6.75*</td>
		</tr>
		<tr>
			<td>(LV+S)/TL (mg/mm)</td>
			<td>20.6 &#177; 1.81</td>
			<td>16.1 &#177; 1.00*</td>
		</tr>
		<tr>
			<td>RV/TL (mg/mm)</td>
			<td>5.76 &#177; 0.53</td>
			<td>10.6 &#177; 2.39*</td>
		</tr>
		<tr>
			<td>RV/(LV+S)</td>
			<td>0.28 &#177; 0.03</td>
			<td>0.66 &#177; 0.16*</td>
		</tr>
		<tr>
			<td>TL (mm)</td>
			<td>39.3 &#177; 1.03</td>
			<td>38.7 &#177; 1.74</td>
		</tr>
	</tbody>
</table>
Table 2: Organ measurements at Day 24 post-MCT (MCT Group) or vehicle (Control Group) administration in Sprague Dawley rats. Data presented as mean &#177; SD. Student&#39;s t-test was used to analyze data. *p &#60; 0.05.&#160;Abbreviations: Monocrotaline (MCT), heart weight (HW), lung weight (LW), right ventricle (RV), left ventricle (LV), and tibia length (TL).

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Comprehensive Echocardiographic Assessment of Right Ventricle Function in a Rat Model of Pulmonary Arterial Hypertension

The present protocol describes the echocardiographic characterization of right ventricular morphology and function in a rat model of pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive disease caused by vasoconstriction and remodeling of the small arteries in the lungs. This ...

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3.3K Views.  University of Illinois at Chicago. The present protocol describes the echocardiographic characterization of right ventricular morphology and function in a rat model of pulmonary arterial hypertension.

Video: Comprehensive Echocardiographic Assessment of Right Ventricle Function in a Rat Model of Pulmonary Arterial Hypertension

Zebrafish Brain Ventricle Injection

Proper brain ventricle formation during embryonic brain development is required for normal brain function.  Brain ventricles are the highly conserved cavities within the brain that are filled with cerebrospinal fluid.  In zebrafish, after neural tube formation, the neuroepithelium undergoes a series of constrictions and folds while it fills with fluid resulting in brain ventricle formation.  In order to understand the process of ventricle formation, and the neuroepithelial shape changes that occur at the same time, we needed a way to visualize the ventricle space in comparison to the brain tissue.  However, the nature of transparent zebrafish embryos makes it difficult to differentiate the tissue from the ventricle space.  Therefore, we developed a brain ventricle injection technique where the ventricle space is filled with a fluorescent dye and imaged by brightfield and fluorescent microscopy.  The brightfield and the fluorescent images are then processed and superimposed in Photoshop.  This technique allows for visualization of the ventricle space with the fluorescent dye, in comparison to the shape of the neuroepithelium in the brightfield image.  Brain ventricle injection in zebrafish can be employed from 18 hours post fertilization through early larval stages.  We have used this technique extensively in our studies of brain ventricle formation and morphogenesis as well as in characterizing brain morphogenesis mutants (1-3).

After neural tube formation, the neuroepithelium constricts and folds while the tube fills with embryonic cerebrospinal fluid (eCSF) to form the embryonic brain ventricles. We developed this ventricle injection technique to better visualize the fluid filled space in contrast to the neuroepithelial shape in a live embryo.

Proper brain ventricle formation during embryonic brain development is required for normal brain function.  Brain ventricles are the highly conserved ...

Right Hemihepatectomy by Suprahilar Intrahepatic Transection of the Right Hemipedicle using a Vascular Stapler

Successful hepatic resection requires profound anatomical knowledge and delicate surgical technique. Hemihepatectomies are mostly performed after preparing the extrahepatic hilar structures within the hepatoduodenal ligament, even in benign tumours or liver metastasis.1-5. Regional extrahepatic lymphadenectomy is an oncological standard in hilar cholangiocarcinoma, intrahepatic cholangio-cellular carcinoma and hepatocellular carcinoma, whereas lymph node metastases in the hepatic hilus in patients with liver metastasis are rarely occult. Major disadvantages of these procedures are the complex preparation of the hilus with the risk of injuring contralateral structures and the possibility of bleeding from portal vein side-branches or impaired perfusion of bile ducts. We developed a technique of right hemihepatectomy or resection of the left lateral segments with intrahepatic transection of the pedicle that leaves the hepatoduodenal ligament completely untouched. 6 However, if intraoperative visualization or palpation of the ligament is suspicious for tumor infiltration or lymph node metastasis, the hilus should be explored and a lymphadenectomy performed.

This video describes a right hemihepatectomy with intrahepatic transection of the right hemipedicle leaving the hepatoduodenal ligament completely untouched.

Successful hepatic resection requires profound anatomical knowledge and delicate surgical technique. Hemihepatectomies are mostly performed after ...

Long-term Silencing of Intersectin-1s in Mouse Lungs by Repeated Delivery of a Specific siRNA via Cationic Liposomes. Evaluation of Knockdown Effects by Electron Microscopy

Previous studies showed that knockdown of ITSN-1s (KDITSN), an endocytic protein involved in regulating lung vascular permeability and endothelial cells (ECs) survival, induced apoptotic cell death, a major obstacle in developing a cell culture system with prolonged ITSN-1s inhibition1. Using cationic liposomes as carriers, we explored the silencing of ITSN-1s gene in mouse lungs by systemic administration of siRNA targeting ITSN-1 gene (siRNAITSN). Cationic liposomes offer several advantages for siRNA delivery: safe with repeated dosing, nonimmunogenic, nontoxic, and easy to produce2. Liposomes performance and biological activity depend on their size, charge, lipid composition, stability, dose and route of administration3Here, efficient and specific KDITSN in mouse lungs has been obtained using a cholesterol and dimethyl dioctadecyl ammonium bromide combination. Intravenous delivery of siRNAITSN/cationic liposome complexes transiently knocked down ITSN-1s protein and mRNA in mouse lungs at day 3, which recovered after additional 3 days. Taking advantage of the cationic liposomes as a repeatable safe carrier, the study extended for 24 days. Thus, retro-orbital treatment with freshly generated complexes was administered every 3rd day, inducing sustained KDITSN throughout the study4. Mouse tissues collected at several time points post-siRNAITSN were subjected to electron microscopy (EM) analyses to evaluate the effects of chronic KDITSN, in lung endothelium. High-resolution EM imaging allowed us to evaluate the morphological changes caused by KDITSN in the lung vascular bed (i.e. disruption of the endothelial barrier, decreased number of caveolae and upregulation of alternative transport pathways), characteristics non-detectable by light microscopy. Overall these findings established an important role of ITSN-1s in the ECs function and lung homeostasis, while illustrating the effectiveness of siRNA-liposomes delivery in vivo.

Repeated retro-orbital injections of cationic liposomes/siRNA/ITSN-1s complexes in mice, every 72 hours for 24 days, efficiently deliver the siRNA duplex to the mouse lung microvasculature reducing ITSN-1s mRNA and protein expression by 75%. This technique is highly reproducible in an animal model, has no adverse effects and avoids fatalities.

Previous  studies showed that knockdown of ITSN-1s (KDITSN), an endocytic  protein involved in regulating lung vascular permeability and endothelial cells ...

A High-throughput Method for Measurement of Glomerular Filtration Rate in Conscious Mice

The measurement of glomerular filtration rate (GFR) is the gold standard in kidney function assessment. Currently, investigators determine GFR by measuring the level of the endogenous biomarker creatinine or exogenously applied radioactive labeled inulin (3H or 14C). Creatinine has the substantial drawback that proximal tubular secretion accounts for ~50% of total renal creatinine excretion and therefore creatinine is not a reliable GFR marker. Depending on the experiment performed, inulin clearance can be determined by an intravenous single bolus injection or continuous infusion (intravenous or osmotic minipump). Both approaches require the collection of plasma or plasma and urine, respectively. Other drawbacks of radioactive labeled inulin include usage of isotopes, time consuming surgical preparation of the animals, and the requirement of a terminal experiment. Here we describe a method which uses a single bolus injection of fluorescein isothiocyanate-(FITC) labeled inulin and the measurement of its fluorescence in 1-2 &mu;l of diluted plasma. By applying a two-compartment model, with 8 blood collections per mouse, it is possible to measure GFR in up to 24 mice per day using a special work-flow protocol. This method only requires brief isoflurane anesthesia with all the blood samples being collected in a non-restrained and awake mouse. Another advantage is that it is possible to follow mice over a period of several months and treatments (i.e. doing paired experiments with dietary changes or drug applications). We hope that this technique of measuring GFR is useful to other investigators studying mouse kidney function and will replace less accurate methods of estimating kidney function, such as plasma creatinine and blood urea nitrogen.

Measurement of glomerular filtration rate (GFR) is the gold standard for kidney function assessment. Here we describe a high-throughput method which allows the determination of GFR in conscious mice by using a single bolus injection, determination of fluorescein isothiocyanate (FITC)-inulin in plasma and calculation of GFR by a two-phase exponential decay model.

The measurement of  glomerular filtration rate (GFR) is the gold standard in kidney function  assessment. Currently, investigators determine GFR by ...

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

The mouse is now the primary animal used to model a variety of lung diseases. To study the mechanisms that underlie such pathologies, phenotypic methods are needed that can quantify the pathologic changes. Furthermore, to provide translational relevance to the mouse models, such measurements should be tests that can easily be done in both humans and mice. Unfortunately, in the present literature few phenotypic measurements of lung function have direct application to humans. One exception is the diffusing capacity for carbon monoxide, which is a measurement that is routinely done in humans. In the present report, we describe a means to quickly and simply measure this diffusing capacity in mice. The procedure involves brief lung inflation with tracer gases in an anesthetized mouse, followed by a 1 min gas analysis time. We have tested the ability of this method to detect several lung pathologies, including emphysema, fibrosis, acute lung injury, and influenza and fungal lung infections, as well as monitoring lung maturation in young pups. Results show significant decreases in all the lung pathologies, as well as an increase in the diffusing capacity with lung maturation. This measurement of lung diffusing capacity thus provides a pulmonary function test that has broad application with its ability to detect phenotypic structural changes with most of the existing pathologic lung models.

Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

We describe a means to quickly and simply measure the lung diffusing capacity in mice and show that it is sufficiently sensitive to phenotype changes in multiple common lung pathologies. This metric thus brings direct translational relevance to the mouse models, since diffusing capacity is also easily measured in humans.

The mouse is now the primary animal used to model a variety of lung diseases. To study the mechanisms that underlie such pathologies, phenotypic methods ...

Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a unique channel-forming member of the ATP Binding Cassette (ABC) superfamily of transporters. The phosphorylation and nucleotide dependent chloride channel activity of CFTR has been frequently studied in whole cell systems and as single channels in excised membrane patches. Many Cystic Fibrosis-causing mutations have been shown to alter this activity. While a small number of purification protocols have been published, a fast reconstitution method that retains channel activity and a suitable method for studying population channel activity in a purified system have been lacking. Here rapid methods are described for purification and functional reconstitution of the full-length CFTR protein into proteoliposomes of defined lipid composition that retains activity as a regulated halide channel. This reconstitution method together with a novel flux-based assay of channel activity is a suitable system for studying the population channel properties of wild type CFTR and the disease-causing mutants F508del- and G551D-CFTR. Specifically, the method has utility in studying the direct effects of phosphorylation, nucleotides and small molecules such as potentiators and inhibitors on CFTR channel activity. The methods are also amenable to the study of other membrane channels/transporters for anionic substrates.

Described here is a rapid and effective procedure for functional reconstitution of purified wild-type and mutant CFTR protein that preserves activity for this chloride channel, which is defective in Cystic Fibrosis. Iodide efflux from reconstituted proteoliposomes mediated by CFTR allows studies of channel activity and the effects of small molecules.

The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a unique channel-forming member of the ATP Binding Cassette (ABC) superfamily of ...

Inducible LAP-tagged Stable Cell Lines for Investigating Protein Function, Spatiotemporal Localization and Protein Interaction Networks

Multi-protein complexes, rather than single proteins acting in isolation, often govern molecular pathways regulating cellular homeostasis. Based on this principle, the purification of critical proteins required for the functioning of these pathways along with their native interacting partners has not only allowed the mapping of the protein constituents of these pathways, but has also provided a deeper understanding of how these proteins coordinate to regulate these pathways. Within this context, understanding a protein's spatiotemporal localization and its protein-protein interaction network can aid in defining its role within a pathway, as well as how its misregulation may lead to disease pathogenesis. To address this need, several approaches for protein purification such as tandem affinity purification (TAP) and localization and affinity purification (LAP) have been designed and used successfully. Nevertheless, in order to apply these approaches to pathway-scale proteomic analyses, these strategies must be supplemented with modern technological developments in cloning and mammalian stable cell line generation. Here, we describe a method for generating LAP-tagged human inducible stable cell lines for investigating protein subcellular localization and protein-protein interaction networks. This approach has been successfully applied to the dissection of multiple cellular pathways including cell division and is compatible with high-throughput proteomic analyses.

We describe a method for generating localization and affinity purification (LAP)-tagged inducible stable cell lines for investigating protein function, spatiotemporal subcellular localization and protein-protein interaction networks.

Multi-protein complexes, rather than single proteins acting in isolation, often govern molecular pathways regulating cellular homeostasis. Based on this ...

A Rapid Automated Protocol for Muscle Fiber Population Analysis in Rat Muscle Cross Sections Using Myosin Heavy Chain Immunohistochemistry

Quantification of muscle fiber populations provides a deeper insight into the effects of disease, trauma, and various other influences on skeletal muscle composition. Various time-consuming methods have traditionally been used to study fiber populations in many fields of research. However, recently developed immunohistochemical methods based on myosin heavy chain protein expression provide a quick alternative to identify multiple fiber types in a single section. Here, we present a rapid, reliable and reproducible protocol for improved staining quality, allowing automatic acquisition of whole cross sections and automatic quantification of fiber populations with ImageJ. For this purpose, embedded skeletal muscles are cut in cross sections, stained using myosin heavy chains antibodies with secondary fluorescent antibodies and DAPI for cell nuclei staining. Whole cross sections are then scanned automatically using a slide scanner to obtain high-resolution composite pictures of the entire specimen. Fiber population analyses are subsequently performed to quantify slow, intermediate and fast fibers using an automated macro for ImageJ. We have previously shown that this method can identify fiber populations reliably to a degree of &#177;4%. In addition, this method reduces inter-user variability and time per analyses significantly using the open source platform ImageJ.

Here, we present a protocol for rapid muscle fiber analyses, which allows improved staining quality, and thereby automatic acquisition and quantification of fiber populations using the freely available software ImageJ.

Quantification of muscle fiber populations provides a deeper insight into the effects of disease, trauma, and various other influences on skeletal muscle ...

Implantation of Electrospun Vascular Grafts with Optimized Structure in a Rat Model

Here, we present a protocol to fabricate macroporous PCL vascular graft and describe an evaluation protocol by using a rat model of abdominal aorta replacement. The electrospun vascular grafts often possess relatively small pores, which limit cell infiltration into the grafts and hinder the regeneration and remodeling of the neo-arteries. In this study, PCL vascular grafts with thicker fibers (5 - 6 &#181;m) and larger pores (~30 &#181;m) were fabricated by using a modified processing technique. The long-term performance of the graft was evaluated by implantation in a rat abdominal aorta model. Ultrasound analysis showed that the grafts remained patent without aneurysm or stenosis occurring even after 12 months of implantation. Macroporous structure improved the cell ingrowth and thus promoted tissue regenerated at 3 months. More importantly, there was no sign of adverse remodeling, such as calcification within the graft wall after 12 months. Therefore, electrospun PCL vascular grafts with modified macroporous processing hold potential to be an artery substitute for long-term implantation.

Here, we present a modified electrospinning method to fabricate PCL vascular grafts with thick fibers and large pores, and describe a protocol to evaluate the in vivo performance in a rat model of abdominal aorta replacement.

Here, we present a protocol to fabricate macroporous PCL vascular graft and describe an evaluation protocol by using a rat model of abdominal aorta ...

Induction of Right Ventricular Failure by Pulmonary Artery Constriction and Evaluation of Right Ventricular Function in Mice

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of RVF. Previous rat models imitating RVF progression have been described. Compared with rats, mice are more accessible, economical, and widely used in animal experiments. We developed a pulmonary artery constriction (PAC) approach which is comprised of banding the pulmonary trunk in mice to induce right ventricular (RV) hypertrophy. A special surgical latch needle was designed that allows for easier separation of the aorta and the pulmonary trunk. In our experiments, the use of this fabricated latch needle reduced the risk of arteriorrhexis and improved the surgical success rate to 90%. We used different padding needle diameters to precisely create quantitative constriction, which can induce different degrees of RV hypertrophy. We quantified the degree of constriction by evaluating the blood flow velocity of the PA, which was measured by noninvasive transthoracic echocardiography. RV function was precisely evaluated by right heart catheterization at 8 weeks after surgery. The surgical instruments made inhouse were composed of common materials using a simple process that is easy to master. Therefore, the PAC approach described here is easy to imitate using instruments made in the lab and can be widely used in other labs. This study presents a modified PAC approach that has a higher success rate than other models and an 8-week postsurgery survival rate of 97.8%. This PAC approach provides a useful technique for studying the mechanism of RVF and will enable an increased understanding of RVF.

Here, we provide a useful approach for studying the mechanism of right ventricular failure. A more convenient and efficient approach to pulmonary artery constriction is established using surgical instruments made inhouse. In addition, methods to evaluate the quality of this approach by echocardiography and catheterization are provided.

The mechanism of right ventricular failure (RVF) requires clarification due to the uniqueness, high morbidity, high mortality, and refractory nature of ...

Comprehensive Echocardiographic Assessment of Right Ventricle Function in a Rat Model of Pulmonary Arterial Hypertension

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Zebrafish Brain Ventricle Injection

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Long-term Silencing of Intersectin-1s in Mouse Lungs by Repeated Delivery of a Specific siRNA via Cationic Liposomes. Evaluation of Knockdown Effects by Electron Microscopy

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Phenotyping Mouse Pulmonary Function In Vivo with the Lung Diffusing Capacity

Functional Reconstitution and Channel Activity Measurements of Purified Wildtype and Mutant CFTR Protein

Inducible LAP-tagged Stable Cell Lines for Investigating Protein Function, Spatiotemporal Localization and Protein Interaction Networks

A Rapid Automated Protocol for Muscle Fiber Population Analysis in Rat Muscle Cross Sections Using Myosin Heavy Chain Immunohistochemistry

Implantation of Electrospun Vascular Grafts with Optimized Structure in a Rat Model

Induction of Right Ventricular Failure by Pulmonary Artery Constriction and Evaluation of Right Ventricular Function in Mice