Ghrelin对雌激素诱导小鼠胸腺细胞凋亡的抑制作用

Inhibitory effect of ghrelin on the estrogen-induced thymocyte apoptosis in mice

6周龄BALB/c雌性小鼠80只,分为4组:雌激素+Ghrelin组、雌激素+生理盐水组、生理盐水组、空白对照组。雌激素+Ghrelin组首先隔日腹腔注射苯甲酸雌二醇(0.1mg/只)2周,然后采用相同方法注射Ghrelin(120μg/只)2周;雌激素+生理盐水组首先注射苯甲酸雌二醇2周,然后注射生理盐水2周;生理盐水组注射生理盐水4周;空白对照组不注射任何试剂。测量各组小鼠的胸腺指数,同时应用光镜、电镜和流式细胞术检测胸腺的显微结构、超微结构和胸腺细胞凋亡率。结果雌激素+Ghrelin组的胸腺指数极显著大于雌激素+生理盐水组,胸腺细胞凋亡率极显著小于雌激素+生理盐水组(P<0.01),而二者与生理盐水组和空白对照组均差异不显著(P>0.05);雌激素+Ghrelin组的胸腺显微结构和超微结构基本恢复正常,并与生理盐水组和空白对照组相似。结论得出Ghrelin可以通过抑制胸腺细胞凋亡和促进胸腺细胞增殖,从而逆转雌激素诱导的小鼠胸腺萎缩。

Eighty six-week-old female BALB/c mice were divided into 4 groups：the estrogen＋ghrelin group,the estrogen＋saline group,the saline group,and the control group.In the estrogen＋ghrelin group,mice were firstly injected intraperitoneally with estradiol benzoate（0.1 mg/per） every other day for 2 weeks,then treated with ghrelin（120 μg/per） for 2 weeks in the same way;in the estrogen＋saline group,mice were firstly administrated with estradiol benzoate for 2 weeks,then saline for 2 weeks;in the saline group,mice were injected with saline for 4 weeks;in the control group mice were out of being treated.Finally,thymus index,microstructure,ultrastructure and thymocyte apoptosis ratio of thymus were determined by using light microscopy,electron microscopy and flow cytometry.The results shows the thymus index in the estrogen＋ghrelin group is extremely higher than that in the estrogen＋saline group,while the thymocyte apoptosis ratio in the estrogen＋ghrelin group is extremely lower than that in the estrogen＋saline group（P0.01）,but they have no significant differences compared with the saline group and the control group（P〈0.05）;and the microstructure and ultrastructure of thymus in the estrogen＋ghrelin group almost returned to normal,resemble to that in the saline group and the control group.The results revealed that ghrelin can reverse estrogen-induced thymus atrophy through inhibiting thymocyte apoptosis and promoting thymocyte proliferation in mice.