Establishment and Confirmation of a Postnatal Right Ventricular Volume Overload Mouse Model

Summary

This protocol presents the establishment and confirmation of a postnatal right ventricular volume overload (VO) model in mice with abdominal arteriovenous fistula (AVF), which can be applied to investigate how VO contributes to postnatal heart development.

Abstract

Right ventricular (RV) volume overload (VO) is common in children with congenital heart disease. In view of distinct developmental stages,the RV myocardium may respond differently to VO in children compared to adults. The present study aims to establish a postnatal RV VO model in mice using a modified abdominal arteriovenous fistula. To confirm the creation of VO and the following morphological and hemodynamic changes of the RV, abdominal ultrasound, echocardiography, and histochemical staining were performed for 3 months. As a result, the procedure in postnatal mice showed an acceptable survival and fistula success rate. In VO mice, the RV cavity was enlarged with a thickened free wall, and the stroke volume was increased by about 30%-40% within 2 months after surgery. Thereafter, the RV systolic pressure increased, corresponding pulmonary valve regurgitation was observed, and small pulmonary artery remodeling appeared. In conclusion, modified arteriovenous fistula (AVF) surgery is feasible to establish the RV VO model in postnatal mice. Considering the probability of fistula closure and elevated pulmonary artery resistance, abdominal ultrasound and echocardiography must be performed to confirm the model status before application.

Introduction

Right ventricular (RV) volume overload (VO) is common in children with congenital heart disease (CHD), which leads to pathological myocardial remodeling and a poor long-term prognosis^1,2,3. An in-depth understanding of RV remodeling and related early targeted interventions is essential for a good outcome in children with CHD. There are several differences in the molecular structures, physiological functions, and responses to stimuli in the hearts of adults and children^1,4,5,

Protocol

All of the procedures presented here conformed to the principles outlined in the Declaration of Helsinki and were approved by the Animal Welfare and Human Studies Committee at Shanghai Children's Medical Center (SCMC-LAWEC-2023-003). C57BL/6 mice pups (P7, males, 3-4 g) were used for the present study. The animals were obtained from a commercial source (see Table of Materials). The mice pups and their nursing mothers (pups:mothers = 6:1 in a single cage) were kept under specific-pathogen-free laborat.......

Discussion

Previously, the classic RV VO model was created using valve regurgitation²¹; however, compared to AVF, open-heart valve surgery may require more sophisticated techniques and may be associated with significantly higher mortality, particularly in postnatal mice. As animal studies have shown that the same effect of VO has been achieved by AVF²², modified abdominal fistula surgery with less trauma was used in this study.

Certain factors were consider.......

Materials

Name	Company	Catalog Number	Comments
70% Ethanol	Tiandz,Chia
ACETAMINOPHEN Oral Solution	VistaPharm, Inc. Largo, FL 33771, USA	NDC 66689-054-01
Anesthesia machine	RWD Life Science,China	R550IP
Anesthesia mask	RWD Life Science,China	68680
C57BL/6 mice	Xipu’er-bikai Experimental Animal Co., Ltd (Shanghai, China)
Hair removal cream	Veet, France	VT-200
Hematoxylin and eosin Kit	Beyotime biotech	C0105M
Isoflurane	RWD Life Science,China	R510-22-10
Microscope	Yuyan Instruments, China	SM-301
Surgical suture needles	NINGBO MEDICAL NEEDLE CO.,LTD, China
Thermostatic heating platform	Qingdao Juchuang Environmental Protection Group Co., Ltd, China
Ultrasound device	FUJIFILM VisualSonics, Inc.	Vevo 2100	Image modes includes B-Mode, Color Doppler Mode and Pulsed Wave Doppler Mode
Ultrasound gel	Parker Laboratories,United States	REF 01-08
Ultrasound transducer	FUJIFILM VisualSonics, Inc.	MS 400