枸杞多糖对大鼠生精细胞热应激后Bcl-2表达的影响

Effects of Lycium Barbarum Polysaccharides on Expression of Bcl-2 of Germ Cells in Rat Exposed to Heat Stress

目的研究枸杞多糖对热应激后睾丸组织形态及生精细胞中Bcl-2表达的影响。方法雄性SD大鼠60只,随机分为正常对照组、热应激组、枸杞多糖高剂量组[100 mg/(kg·d)]、枸杞多糖中剂量[50 mg/(kg·d)]、枸杞多糖低剂量组[10 mg/(kg·d)]。枸杞多糖组大鼠按上述剂量给予枸杞多糖连续灌胃14 d,正常对照组、热应激组则给予等量的生理盐水灌胃,热应激组和枸杞多糖组大鼠于第15 d给予43℃水浴30 min。热应激后24 h、48 h颈椎脱臼处死大鼠。HE染色观察睾丸组织形态学变化,TUNEL法检测生精细胞凋亡,免疫组化法检测睾丸生精细胞Bcl-2的表达。结果各枸杞多糖组大鼠的睾丸指数及生精小管直径较热应激组显著增加(P<0.05),凋亡指数明显降低(P<0.05),生精细胞中Bcl-2表达显著增加(P<0.05)。结论枸杞多糖可能通过促进Bcl-2的表达,从而抑制生精细胞的凋亡,起到保护睾丸组织的作用。

Objective To investigate the effects of Lycium barbarum polysaccharides （LBP） on histological exami- nation in testes and the expression of Bcl - 2 of germ cells after heat stress. Methods Sixty male Sprague - Dawley rats were randomly divided into five groups： control, heat stress （HS） , high - dose LBP [ 100 mg/（kg· d） ] , median - dose LBP [50 mg/（ kg ·d） ] and low -dose LBP [10 mg/（ kg · d） 1. The rats of these three LBP groups were given LBP according to the doses mentioned above by intragastric administration respectively for 14 days, while others were given equal physiological saline. And on the 15th day the rats of LBP groups, together with those of the HS group, were exposed to a heat of 43℃for 30 minutes. Twenty - four hours and forty - eight hours after heat shock, animals were killed by cervical dislocation. The his- tological examination of testes was analyzed by HE staining. The detection of apoptotic germ cells used TUNEI, and the ex- pression of Bcl - 2 in germ ceils were detected by immunohistochemistry. Results Compared with the HS group, not only the diameter of seminiferous tubule, but also the testicular index of the rats in these three LBP groups increased significantly （ P 〈 0.05 ）. There was an obvious decrease in apoptosis index in three LBP groups （ P 〈 0.05 ）. And the expression level of Bcl - 2 in germ cells decreased significantly in all LBP groups （ P 〈 0.05 ）. Conclusion LBP can increase Bcl - 2 expres- sion on germ cells which makes to inhibit apoptosis of germ cells, so that the testicular tissue can be protected.