右冠状动脉缺血再灌注致窦房结及其周围心房肌细胞的不均一凋亡

目的　观察右冠状动脉缺血再灌注(IR)致兔窦房结及其周围心房肌细胞的凋亡规律。方法　成年家兔2 2只,其中模型对照组10只,IR模型组12只用于在体右冠状动脉根部结扎或放松制作窦房结缺血6 0 min、再灌注6 0 min模型,采用末端标记TU NEL 法检测窦房结中央、窦房结周边及其周围心房肌细胞凋亡率及光、电镜下结构变化。结果　(1) IR组有8只(8/ 12 )窦房结及其周围心房肌均有细胞凋亡现象,其凋亡率(% )分别为11.3±3.7、15 .0±4 .5和2 4 .4±5 .9;(2 )光镜下,IR组窦房结起搏细胞边界不清,胞核固缩,胞浆嗜酸性增强,细胞呈腺样排列;电镜下,心房肌细胞呈明显凋亡征象。结论　IR可诱导窦房结及其周围心房肌细胞呈梯度不均一凋亡,且窦房结中央凋亡率最低。

Inhomogenous apoptosis right coronary artery ischemia-reperfusion on apoptosis of sino-atrial node and its peripheral atrial myocardial cells in rabbit

Objective Heterogenous apoptosis of sino-atrial node and its peripheral atrial myocardial cells caused by ischemia-reperfusion of right coronary artery in rabbit.Methods The IR injury models of SAN were established by occluding or loosening the root of right coronary artery for ischemia-60 min and reperfusion-60 min respectively in 12 healthy adult rabbits.Distribution of the apoptosis of SAN and its peripheral atrial myocardial cells was detected by TUNEL staining and the changes of their structure were observed under the light and electron microscope.Results (1)The apoptosis was found in 8 rabbits(8/12 rabbits) in the center and peripheral region of SAN as well as peripheral atrial myocardium were found, and their apoptosis rates were 11.3%±3.7%,15.0%±4.5% and 24.4%±5.9% respectively.(2)In IR rabbits,indistinct margin,nucleus pycnic,enhanced eosinophilic staining and adeniform arranged cells wers found under microscope,and obvious apoptosis of aterial myocardium cells was observed under eledron microscope.Conclusion IR can induce inhomogenous apoptosis in SAN and its peripheral atrial myocardium,and the apoptosis rate of the SAN center is the lowest compared with the peripheral region and it's peripheral atrial myocardium.