In vivo noninvasive detection of vulnerable atherosclerotic plaque by 99Tcm-annexin Ⅴ imaging in an atherosclerotic rabbit model
10.3321/j.issn:0253-3758.2008.10.015
- VernacularTitle:99锝m标记膜联蛋白Ⅴ检测细胞凋亡评价动脉粥样斑块的实验研究
- Author:
Jin-Peng XU
1
;
Quan-Ming ZHAO
;
Xiao-Li DONG
;
Qian WANG
;
Dong CHEN
;
Hong-Zhi MI
;
Hui-Feng DU
;
Zhan-Min XU
Author Information
1. 河北大学附属医院
- Keywords:
Atherosclerosis;
Radionuclide imaging;
Annexius;
Technetium;
Apoptosis
- From:
Chinese Journal of Cardiology
2008;36(10):921-926
- CountryChina
- Language:Chinese
-
Abstract:
Objective Apoptosis contributes to the instability of the atheresclerotie (AS) lesions.The vulnerable plaque was identified in vivo by detecting the apoptosis with radiolabeled annexin Ⅴ in an atherosclerotic rabbit model Methods Eight male New Zealand white rabbits on 2% cholesterol diet for 2 weeks had abdominal aortic balloon injury and fed a 2% cholesterol diet for another 15 weeks (AS group),3 rabbits fed a normal rabbit chow for 17 weeks without balloon injury served as contrels.Annexin Ⅴ labeled with 99Tcm was then intravenously administered and planar whole-body images were captured using a gamma camera in the left lateral position.The entire length of the abdominal aorta was explanted for ex vivo imaging with gamma camera.The aorta then was divided into several segments according to the severity of AS.The segments were separated weighted and counted in an gamma counter for the absorptive dose of annexin per gram of tissue.Histology examinations were made on specimens.Results At 2 hours post annexin Ⅴ injection,clear delineation of radiolabel within the abdominal aorta could be evidenced in vivo gamma.imaging.After explanation of the aorta,ex vivo imaging showed a robust uptake of radiotracer in the infradiaphragmatic aorta corresponding to the in vivo images and conforming to the macroscopic distribution of atherosclerotic lesions.The uptake of radiolabel was absent in areas without grossly visible atheroeclerotic lesions.The in vivo and ex vivo images identified plaque areas were identical and corresponded histological results on the explanted specimen.The aortic specimen was divided into 18 segments on lesions.The magnrity of the lesions (14/18) manifested as type Ⅳ or type Ⅴ lesions of AHA classification (vulnerable lesions),except segmentsl-4,which manifested as type Ⅰ or type Ⅱ lesions.The thickness of fibrous cap (TFC) and the ratio of cap and lipid nuclear (RCN) were significantly reversely correlated to the unit radioactivity counts,and the correlation between RCN and the unit radioactivity counts was more significant than that between TFC and the unit radioactivity counts (r=-0.904,P＜0.01,and r=-0.8,P＜0.01).Apoptosis detection (TUNEL):annexin Ⅴ intake in plaques was positively correlated to apoptotic index(r=0.651,P=0.012).Conclusion Noninvasive Annexin Ⅴ imaging could be used to detect vulnerable atherosclerotic plaques in vivo.
