A novel animal model for vulnerable atherosclerotic plaque: dehydrated ethanol lavage in the carotid artery of rabbits fed a Western diet

Ruochi Zhao; Hongyan Liu; Shangshi Zhang; Qi Lu; Xiaohong Fei; Honglin Zhou; Junsong Liu; Honghua Ye; Xiaomin Chen; Hanbin Cui

doi:10.21037/cdt-21-291

A novel animal model for vulnerable atherosclerotic plaque: dehydrated ethanol lavage in the carotid artery of rabbits fed a Western diet

Cardiovasc Diagn Ther. 2021 Dec;11(6):1241-1252. doi: 10.21037/cdt-21-291.

Authors

Ruochi Zhao^#¹, Hongyan Liu^#², Shangshi Zhang³, Qi Lu⁴, Xiaohong Fei¹, Honglin Zhou¹, Junsong Liu¹, Honghua Ye¹, Xiaomin Chen¹, Hanbin Cui¹

Affiliations

¹ Cardiology Center, Ningbo First Hospital, Ningbo University, Ningbo, China.
² Neurology Department, Ningbo First Hospital, Ningbo University, Ningbo, China.
³ Cardiovascular Department, Shangrao People's Hospital, Shangrao, China.
⁴ Cardiovascular Department, Yinzhou People's Hospital, Ningbo University, Ningbo, China.

^# Contributed equally.

Abstract

Background: The study of unstable atherosclerotic plaques is limited by the absence of ideal animal models to reproduce the plaque instability observed in humans. In this study, we attempted to develop a novel animal model for vulnerable atherosclerotic plaques using dehydrated ethanol lavage in rabbits fed a Western diet (WD).

Methods: A total of 30 New Zealand White (NZW) rabbits were randomized to 5 groups, including a control group with or without WD, a balloon injury with WD group, and an ethanol injury with or without WD group. Operations were conducted using the right common carotid artery as the target vessel. All animals were followed up for 3 months unless a vascular event occurred. Blood samples and carotid artery specimens were ultimately collected for analysis of atherogenesis.

Results: Compared to rabbits in which lesions were induced by balloon injury, those subjected to an ethanol lavage with high cholesterol diet showed progressive atherosclerotic lesions in all carotid artery segments, which were characterized by greater plaque burden, smaller minimum lumen area (MLA), and increased vulnerability as indicated by abundant macrophages, scattered smooth muscle cell (SMC) composition, higher matrix metalloproteinase-9 (MMP-9) expression in plaques, thinner fibrous cap thickness, and higher possibility of stroke event (50% vs. 0%). Meanwhile, the serum interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) levels in the ethanol injury group with a high-cholesterol diet were significantly higher than those in the balloon injury group after 3 months (all P<0.01).

Conclusions: We successfully established a novel animal model for vulnerable atherosclerosis by ethanol exposure of the carotid segment that has a higher predictive value for the probability of ischemic events than the balloon injury model. Therefore, it may represent a promising animal model for investigating new therapeutic approaches, novel imaging modalities, and underlying mechanisms for vulnerable atherosclerotic plaque.

Keywords: Animal model; endothelial cell (EC) injury; inflammatory marker; vulnerable atherosclerotic plaque.