IGF-I对NOD鼠胰岛Fas/FasL表达的影响

Effect of IGF-I on Fas/FasL expression in pancreatic islets from NOD mice

目的 观察腹腔注射胰岛素样生长因子 Ⅰ (IGF Ⅰ )对NOD鼠胰岛炎和糖尿病的发生情况以及其对胰岛Fas FasL表达的影响。方法 2 0只 4周龄NOD雌鼠随机分为 2组 ,每组 10只 ,实验组每周 2次腹腔注射 1mlIGF Ⅰ(40ng ml) ,对照组注射 1ml生理盐水 ,共 8周。实验动物在发生糖尿病 7天后或至 2 0周龄处死 ,观察血清胰岛素及C肽浓度、胰岛HE染色、免疫组织化学染色 检测胰岛Fas FasL的表达。结果 IGF Ⅰ可明显减少NOD鼠胰岛炎和糖尿病的发生 (P <0 .0 1) ;IGF Ⅰ组胰岛Fas的表达少于对照组 (P <0 .0 1) ;FasL的表达多于对照组 (P <0 .0 1)。结论 早期应用IGF Ⅰ腹腔注射可以减少NOD鼠的胰岛炎症和糖尿病发生 ,其机制与Fas FasL介导的胰岛B细胞凋亡有关。

Objective To determine the effects of IGF-Ⅰ on Fas/FasL expression in islets of Langerhans from NOD mice and seek whether IGF-Ⅰ intervenes in development of insulitis and diabetes mellitus.Methods Twenty female NOD mice were divided into two groups.10 mice were injected intraperitoneally (ip) IGF-Ⅰ 1ml (40ng/ml) at 4 weeks old twice a week for 8 weeks as study group(SG),the same volume of normal saline(NS) was given to the other 10 mice as control group(CG).The mice were killed at 20 weeks old or 7days after diagnosis of diabetes.The serum levels of insulin and c-peptide were measured.Insulitis and Fas/FasL expression were investigated by HE and immunohistochemical staining of pancreatic tissues.Results IGF-Ⅰ could abate the extent of insulitis and reduce the number of diabetes mellitus onset in SG(P<0.01).Fas expression in the SG was less than that in the CG(P<0.01).FasL expression in SG was more than that in CG.Conclusion Early use of IGF-Ⅰ has been shown a protective effects on the development of insulitis and diabetes.Fas/FasL-mediated B cell apoptosis may play a role.