旋覆花素对过度训练致急性心肌损伤大鼠caspase-3和细胞色素c表达的影响

Effects of Inula Britannica on myocardial caspase-3 and cytochrome C expression following overtraining-induced acute myocardial injury in rats

目的探讨旋覆花素对过度训练致急性心肌损伤大鼠半胱氨酸天冬氨酸酶-3（caspase-3）和细胞色素C表达的影响。方法雄性Wistar大鼠48只，体重200～220g，采用随机数字表法，将其随机分为3组：正常对照组（C组，n=8）、过度训练组（E组，n=24）和旋覆花素组（IB组，n=16）。E组和IB组采用游泳致力竭法制备过度训练致大鼠急性心肌损伤模型。IB组于过度训练前24h及过度训练前即刻分别经口灌入旋覆花素25ml／kg。E组于过度训练后即刻、6、24h时，IB组于过度训练后6、24h时分别取8只大鼠，采集下腔静脉血样，采用ELISA法检测血清心肌肌钙蛋白I（cTnI）浓度；然后处死大鼠，取心肌组织，采用免疫组化法检测心肌组织caspase-3和细胞色素C表达，光镜下观察心肌组织病理学结果。结果与C组比较，E组和IB组过度训练后各时点血清cTnI浓度升高，心肌组织caspase-3与细胞色素C表达上调（P〈0．05）；与E组比较，IB组过度训练后6、24h时血清cTnI浓度降低，心肌组织caspase-3与细胞色素c表达下调（P〈0．05）。IB组心肌损伤程度轻于E组。结论旋覆花素可减轻过度训练致大鼠急性心肌损伤，其机制与下调心肌组织caspase-3及细胞色素C表达有关。

Objective To investigate the effects of Inula Britannica on myocardial caspase-3 and cytochrome c （cyt c） following overtraining-induced acute myocardial injury in rats. Methods Forty-eight male Wistar rats weighing 200-220 g were randomly divided into 3 groups： group control （group C, n = 8） ; group exhausting swim （group E, n = 24） and group Inula Britannica （group IB, n = 16）. The animal model of overtraining-induced acute myocardial injury was developed by exhausting swim. The animals were forced to swim until they were exhausted. The animals sank to the bottom and no righting reflex or escape response was elicited when they were taken out of water in groups E and IB. In group IB oral Inula Britannica 25 ml/kg was given 24 h and immediately before overtraining. Blood samples were taken from inferior vena cava immediately and at 6, 24 h after overtraining in group E and at 6,24 h after overtraining in group IB for determination of serum cardiac troponin I （cTnI） concentration （by ELISA）. The animals were sacrificed after blood sampling and myocardial specimens were obtained for microscopic examination and determination of caspase-3 and cyt c expression （by immuno-histochemistry）. Results Overtraining significantly increased serum cTnI concentration and up-regulated myocardial caspase-3 and cyt c expression in group E as compared with group C. Oral Inula Britannica significantly attenuated overtraining-induced increase in serum cTnI concentration and myocardial caspase-3 and cyt c expression in group IB as compared with group E. Conclusion Inula Britannica can reduce overtraining-induced acute myocardial injury by down-regulating caspase-3 and cyt c expression.