心肌缺血对大鼠房室交界区的形态学影响

EFFECT OF MORPHOLOGY OF ATRIOVENTRICULAR JUNCTION AREA OF RAT ON MYOCARDIAL ISCHEMIA

目的 :在大鼠心肌缺血模型上研究房室交界区 (房室结及房室束 )的形态学变化。方法 :SD大鼠 2 0只 ,分为 2 4h实验组、48h实验组、72h实验组和对照组 ,实验组皮下注射去甲肾上腺素 5mg/Kg。取材心房室交界区 ,常规石蜡切片 ,HE或Masson三色染色 ,光镜下观察和照相。结果 :3个缺血实验组一般心肌光镜下的形态学改变均已出现 ;72h实验组的房室交界区表现为传导细胞边界不清 ,胞浆嗜酸性增强 ,细胞核染色加深 ,传导细胞间的毛细血管扩张 ,而且房室束区的缺血变化比房室结区严重。结论 :心肌缺血时 ,传导系统缺血的情况没有一般心肌严重 ,没有一般心肌反应快 ,分布也不均匀 。

Objective:To study the morphological changes of atrioventricular junction area (atrioventricular node and atrioventricular bundle) on the myocardial ischemia model of rat.Methods:20 rats were divided into 24h group,48h group,72h group and control group.The rats of three experiment groups were injected by isoproterenal(5mg/Kg) subcutaneously.The tissues containing atrioventricular of rats,embedded in paraffin and cut serially,and stained by Masson trichroism or HE.The sections were observed under microscopy and got photographed.Results:The three experiment ischemia groups showed the morphological changes of general myocardial fibers under microscopy,the 72 experiment group showed the unclear of periphery of conducting cells,the eosinophil in cytoplasm stronger,the stain in cell nucleus deeper, the volume of capillary between conducting cells larger.The changes of ischemia in atrioventricular bundle were more than that in atrioventricular node.Conclusion:When there were myocardial ischemia in heart the changes of ischemia in general myocardial fibers were stronger than in conduction system of heart.The reactions for ischemia in conducting tissues were slower than in general myocardial fibers,the distribution of the changes for ischemia were uneven in conduction system.From posterior part of atrioventricular node to atrionventricular bundle, the morphological changes for myocardial aschemia got more serious.