^99Tc^m-HYNIC-Annexin V动脉粥样硬化显像的实验研究

Research on the ^99Tc^m-HYNIC-Annexin V scintigraphy of rabbit atherosclerotic lesions

目的探讨^99Tc^m-联肼尼克酰胺（HYNIC）-膜联蛋白V（Annexin V）显像检测兔动脉粥样硬化（AS）病变的价值。方法5只雄性日本大耳白兔通过免疫损伤血管和12周高脂饮食制备成AS模型（实验组），白兔耳缘静脉按体质量注射^99Tc^m-HYNIC-Annexin V 37MBq／kg，分别行活体和离体血管的^99Tc^m-HYNIC—Annexin V显像。5只未经特殊处理的同种白兔行活体显像作为对照。对实验组兔的主动脉分段后，测定各片段质量和放射性计数，并进行病理学和免疫组织化学检查。采用SPSS 13．0软件对数据进行统计学处理。结果显像剂注射后2h，实验组兔主动脉可见放射性摄取达峰值，而对照组未见明显的放射性摄取，前者靶／非靶（T／NT）比值（2．70±0．26）明显高于后者（1．30±0．13，t=1．99，P〈0．05）。实验组兔的主动脉血管斑块片段放射性摄取（每克组织百分注射剂量率，％ID／g）为（0．075±0．016）％ID／g，明显高于非斑块血管片段[（0．035±0．013）％ID／g，前者是后者的（4．55±0．99）倍，t=4．77，P〈0．001]；两者的凋亡细胞指数（AI）分别为（40．53±14．94）％和（11．90±7．09）％，差异具有统计学意义（t=2．54，P〈0．01）。所有血管片段的放射性摄取（％ID／g值）与AI呈正相关（r=0．98，P〈0．001）。结论^99Tc^m-HYNIC-Annexin V可以无创性地检测AS斑块的凋亡。

Objective The aim of this study was to investigate the value of ^99Tc^m-hydrazino-nictinamide （HYNIC）-Annexin V scintigraphy in the detection of rabbit atherosclerotic lesions. Methods Five Japanese male rabbits, which received immune injury of arteries combined with 12 weeks of high fat diet, underwent scintigraphy after injection of 37 MBq/kg ^99Tc^m-HYNIC-Annexin V. Another 5 rabbits were studied as control. The aortas of the atherosclerotic rabbits were explanted for ex vivo imaging and then cut into segments for radioactive detection and histological characterization of the lesions. SPSS 13.0 was used to analyse the data. Results In compared with the controls, study groups showed significantly high uptake of ^99Tc^m-HYNIC-Annexin V （2.70 ± 0.26 vs 1.30 ± 0.13, t = 1.99, P 〈 0.05） at 2 h after injection. Moreover, higher ^99Tc^m-HYNIC-Annexin V ratio [ （4. 55 ±0.99）-fold], higher activity （the percentage of injected dose per gram, % ID/g） at plaque vs non-plaque segments [ （0.075 ±0.01 ） % ID/g vs （0.035±0.01） %ID/g, t =4.77, P〈0.001] and high apoptotic index [AI, （40.53 ±14.94）% vs （11.90 ± 7.09） %, t =2. 54, P 〈0.01 ] were also noted. Furthermore, positive correlation was noted between % ID/g and AI （r =0.98, P 〈0.001 ）. Conclusion ^99Tc^m-HYNIC-Annexin V scintigraphy has a potential value in identifying the apoptosis of atherosclerotic plaques in rabbit models.