茶多酚及耐力运动对高脂膳食大鼠肝细胞凋亡的影响

Influence of Tea Polyphenols and Endurance Training on the Apoptosis of Liver Cells of Fat-Rich Diet Rats

目的:探讨茶多酚及耐力运动对高脂膳食大鼠肝脏细胞凋亡的影响。方法:雄性SD大鼠64只,随机分为2个大组,即安静组和运动组;每个大组再各分为4个小组:对照组(A、E)、高脂膳食组(B、F)、高脂膳食+低剂量茶多酚组(C、G,150 mg/kg体重)和高脂膳食+高剂量茶多酚组(D、H,300 mg/kg体重)。运动组进行每天1次60 min的耐力运动训练,6周后取肝脏组织,常规HE染色观察肝脏组织结构的变化,免疫组织化学法观察凋亡蛋白表达的差异,原位细胞凋亡法(TUNEL)检测凋亡指数的不同。结果:HE观察显示,安静状态下高脂膳食导致大鼠肝脏细胞出现明显的脂肪性变,茶多酚补充及耐力运动都使脂肪性变得到改善,高剂量茶多酚组优于低剂量组,二者联合作用后,大鼠肝脏细胞结构基本恢复正常。安静状态下高脂膳食组大鼠肝细胞Bax/Bcl-2与对照组比较显著增大;茶多酚补充使Bax表达水平降低,但对Bcl-2的表达没有影响,Bax/Bcl-2比高脂膳食组显著降低;6周耐力运动促使高脂膳食大鼠肝细胞Bax及Bcl-2的表达水平下降,Bax/Bcl-2与高脂膳食安静组没有差异;耐力运动联合茶多酚作用后,使高脂膳食大鼠肝细胞Bax及Bcl-2表达量降低,Bax/Bcl-2显著下降至安静对照组水平。高脂膳食组大鼠肝细胞凋亡指数极显著增加,茶多酚和耐力运动均促使凋亡指数下降,二者联合作用后,凋亡指数进一步降低。结论:高脂膳食导致大鼠肝细胞脂肪性变,细胞凋亡增加;茶多酚和耐力运动都降低了肝细胞凋亡指数,改善了肝细胞结构;二者联合作用的效果优于单纯的耐力运动和茶多酚补充。

Objective：To explore the influence of tea polyphenols and endurance training on the apoptosis of liver cells of fat-rich diet rats.Methods：First,64 SD male rats were randomly divided into 2 groups：quietness group and endurance training group.Then each group was divided into 4 subgroups：control group（A and E）,fat-rich diet group（B and F）,fat-rich-diet and low-tea-polyphenols group（C and G,150mg/kg）,fat-rich-diet and high-tea-polyphenols group（D and H,300mg/kg）.The training group received a 60min endurance training every day.Six weeks later,the livers of the rats were removed from the body,being observed the histo-structure by the routine stained hematoxylin-eosin（HE）,and the variations of apoptois protein expressions by the immunohistochemisty technology,and the differences of the apoptotic index by TUNEL.Results：Observed by HE,obvious steaosis was found in the liver cells of the fat-rich-diet group in the quiet state.Both absorption of tea polyphenols and the endurance training can improve the steatosis,and the high-tea-polyphenols group do better than the low-tea-polyphenols group.If the two combined,the liver cell structure of the fat-rich diet rats can be kept in a normal level.In a quite state,the ratios of Bax/Bcl-2 in the fat-rich diet rats group are higher than those of the control group;the absorption of tea polyphenols results in a down-regulation Bax expression,but exerted no influence on Bcl-2 expression,and both of the ratios going downward and lower than those of the control group.6 weeks endurance training lead to the fall of the Bax and Bcl-2 expression in the liver cells of the fat-rich diet rats,and the ratios of Bax/Bcl-2 has no difference from the control group.Endurance training combined with tea polyphenols absorption causes a downward Bax and Bcl-2 expression,and the ratios of Bax/Bcl-2 dropped apparently,coming back to the same level as that of the quietness group.The fat-rich diet causes a remarkable increase of the apoptosis index of liver cells of the rats,but the endurance training or tea polyphenols can make a decrease of the apoptosis index,and if the two combined together,the apoptosis index can drop further.Conclusion：The fat-rich diet causes steatosis and increase of apoptosis in the liver cells.Both the endurance training and tea polyphenols can decrease the apoptosis of liver cells and improve the cell structure,and if the two combined,a better result is found.