摘要
目的:制备大鼠在体缺血再灌注模型,观察缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性的变化。方法:实验于2005-03/2006-10在解放军沈阳军区总医院医学实验动物中心和全军心血管研究所实验室完成。实验分组:选用健康雌性SD大鼠36只,根据预适应程序分为第1,2,3次缺血,第1,2,3次再灌注,每一时间点6只大鼠。实验过程:用手术套管法造成左冠状动脉主干缺血及再灌注。所有实验动物在实验程序结束后,取出心脏迅速置液氮保存备用。实验评估:用放射免疫法测环磷酸腺苷水平,生化法测环磷酸腺苷依赖蛋白激酶活性变化。结果:36只大鼠均进入结果分析。①环磷酸腺苷含量:第1次再灌注组低于第1次缺血组[(0.325±0.015),(0.395±0.024)pmol/g,t=6.06,P<0.001],第2次再灌注组低于第2次缺血组[(0.523±0.017),(0.708±0.067)pmol/g,t=6.56,P<0.001],第3次再灌注组低于第3次缺血组[(0.567±0.031),(0.712±0.038)pmol/g,t=7.24,P<0.001]。②环磷酸腺苷依赖蛋白激酶活性:第1次再灌注组低于第1次缺血组[(10.115±1.000),(16.351±0.849)pkat/g,t=11.12,P<0.001],第2次再灌注组低于第2次缺血组[(11.877±2.213),(14.869±0.619)pkat/g,t=3.31,P<0.01],第3次再灌注组低于第3次缺血组[(11.745±0.987),(14.766±0.329)pkat/g,t=7.09,P<0.001]。③缺血预处理程序中心肌环磷酸腺苷含量及环磷酸腺苷依赖蛋白激酶活性随缺血及再灌注呈周期性波动。在5min缺血预处理时表现为明显增高,而在间隔的再灌注程序中恰呈相反改变,有明显下降的趋势。结论:环磷酸腺苷及环磷酸腺苷依赖蛋白激酶的周期性波动变化可能是激发心肌缺血预处理的机制之一,环磷酸腺苷可能在预处理保护作用中起一些作用。
AIM： To observe the changes of the content of cyclic-adenosine monophosphate （cAMP） and the activity of protein kinase A （PKA） during the procedure of preconditioning in rat myocardium of ischemia/reperfusion model in vivo. METHODS： This experiment was completed in the Experimental Animal Center of General Hospital of Shenyang Military Area Command and the Research Institute of Chinese PLA Cardiovascular Diseases between March 2005 and October 2006. In the preconditioning procedure, 36 female SD rats were randomly divided into three ischemia groups and three reperfusion groups, each group contained 6 rats. Rats underwent left coronary artery occlusion and reperfusion using cuff technique. At the end of the experiment, the rat hearts were excised and stored in liquid nitrogen until the time of assay. The activity of PKA was analyzed by the method of biochemistry and the content of cAMP was examined by radioimmunoassay. RESULTS： All 36 rats were involved in the result analysis.①cAMP content： The contents of cAMP in rats were lower in the reperfusion groups than in the ischemia groups at the corresponding time points [（0.325±0.015）, （0.395±0.024） pmol/g, t=6.06, P〈0.001; （0.523±0.017）, （0.708±0.067） pmol/g, t =6.56, P〈0.001; （0.567±0.031）, （0.712±0.038） pmol/g, t =7.24, P 〈 0.001].②PKA activity： The activity of PKA in rats were lower in the reperfusion groups than in the ischemia groups at the corresponding time points [（10.115±1.000）, （16.351±0.849） pkat/g, t=11.12, P 〈 0.001; （11.877±2.213）, （14.869±0.619）pkat/g, t=3.31, P 〈 0.01; （11.745±0.987）, （14.766±0.329） pkat/g, t =7.09, P 〈 0.001].③Dudng the procedure of preconditioning, the content of cAMP and the activity of PKA varied with ischemia/reperfusion in a marked fluctuation manner, and both showed a sharp increase when hearts were exposed to three episodes of 5-minute ischemia, and almost completely reversed by each reperfusion period that presented obvious decrease. CONCLUSION： The fluctuation of cAMP and PKA probably elicits the protection of ischemic preconditioning, which can afford some protection to heart through myocardial cAMP content.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2007年第29期5725-5728,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
