枸杞多糖对热应激大鼠生精细胞Bax和CytC表达的影响

Effects of Lycium barbarum polysaccharides on the expressions of Bax and cytochrome c of germ cells in rat exposed to heat stress

目的研究枸杞多糖（LBP）对热应激睾丸组织形态学及生精细胞中Bax和细胞色素C（cytochrome c，Cyt C）表达的影响。方法90只雄性SD大鼠，随机分为正常对照组、热应激组、LBP高剂量组（100mg／kg·d-1）、中剂量（50mg／kg·d-1）和低剂量组（10mg／kg·d-1）。LBP组大鼠按以上剂量给予LBP连续灌胃14d，正常对照组及热应激组给予等量生理盐水灌胃，于第15天给予热应激组和LBP组大鼠43℃水浴30min。于热应激后1d、2d和7d，分别处死各组大鼠，取出睾丸组织。采用HE染色观察睾丸组织形态学变化，免疫组化法检测睾丸生精细胞Bax和CytC的表达。结果与热应激组比较，各LBP组大鼠的体质量、睾丸质量、睾丸指数及生精小管直径显著增加（P〈0.05），生精细胞中Bax和CytC的表达显著降低（P〈0.05），以1Omg／kg·d-1。组效果最为明显。结论LBP可能通过抑制Bax的活化，从而抑制CytC自线粒体释放到胞浆，进而减少Caspase-3的活化，通过线粒体途径起到保护睾丸组织的作用。

Objective To investigate the effects of LBP on histological morphology of testes and the expressions of Bax and cytochrome c of germ cells under heat stress. Methods Ninety male Sprague-Dawley rats were randomly divided into the control group, heat stress（HS） group, high-dose LBP group（100mg/kg·d-l）, median-dose LBP group（50mg/kg·d-1） and low-dose LBP group（10mg/kg·d-1）. The rats in three LBP groups were given LBP for 14 days according to the doses mentioned above by intragastric administration respectively, while others were given equal physiological saline. On the 15th day, the rats in LBP groups, together with those in the HS group, were exposed to a heat of 43℃ for 30 minutes. According to day 1,2 and 7 after local testicular heating, each group was divided into 3 subgroups（n=6）. The histological morpology of testes was analyzed by HE staining, and the expressions of Bax and cytochrome c in germ cells were detected by immunohistochemistry. Results Compared with those of the HS group, the weight （at ld and 7d after heat stress） and the diameter of seminiferous tubule, the testicular weight and index of the rats in these three LBP groups were all increased significantly （P〈0.05）. And the expressions of Bax and cytochrome c in germ cells were decreased significantly （P〈0.05）. And the dose of 10mg/kg·d-1 had the best effect. Conclusion LBP decreased the damnification of testes in exposure to heat stress which might be associated to regulation of Bax and cytochrome c in germ cells.