title: Angiotensin II-accelerated vulnerability of carotid plaque in a cholesterol-fed rabbit model-assessed with magnetic resonance imaging comparing to histopathology.
abstract: This study sought to reveal the effect of angiotensin II (Ang II)-induced atherosclerotic vulnerability in rabbits and to determine whetherin vivomagnetic resonance imaging (MRI) can determine the effect of Ang II on atherosclerotic development over time. In total, 24 elderly male New Zealand white rabbits underwent an intravascular balloon injury in the left common carotid artery (LCCA) and were subsequently fed a high cholesterol diet for 12 weeks. At 8 weeks, rabbits were randomly assigned to receive either Ang II (1.4 mg/kg/d, Ang II group) or vehicle (phosphate-buffered saline, control) via a subcutaneous osmotic minipump for 4 weeks. The rabbits were imaged three times: at baseline and at 8 and 12 weeks. After the 12-week MRI scanning, rabbits were euthanized to obtain pathological and histological data. Atherosclerotic plaques were identified in the 21 rabbits that survived the 12-week trial. Typical feature of vulnerable plaques (VP), intraplaque hemorrhage, were observed in 6 of 10 animals (60.0%) in the Ang II group. The CohenKvalue of MR imaging between the AHA classifications was 0.82 (0.73-0.91;P< 0.001). MRI revealed that the change in carotid morphology were significantly different between the Ang II and control group plaques. Our results support an important role for Ang II in plaque vulnerability by promoting intraplaque neovascularization and hemorrhage as well as inflammation. The vulnerable features induced by Ang II in rabbit carotid plaques could be accurately monitored with MRIin vivoand confirmed with histomorphology.
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Sun
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Huilin
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Yao
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Xiaosheng
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Department of Neurosurgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Jieqing
authors.initials: J
authors.lastname: Wan
authors.affiliation: Department of Radiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200127, China.
authors.forename: Jianrong
authors.initials: J
authors.lastname: Xu
keywords: Angiotensin II; Carotid artery; Magnetic resonance imaging; Rabbit model; Vulnerability