摘要
目的观察甲状腺素对SD大鼠胰岛β细胞凋亡核苷酸、半胱氨酸天冬氨酸蛋白酶3(caspase-3)、B细胞淋巴瘤/白血病基因2蛋白(Bcl-2),肝细胞过氧化物酶增殖体激活受体γ(PPARγ)和葡萄糖转运蛋白2(GLUT2)表达影响,以探讨甲状腺功能亢进时合并糖尿病或葡萄糖耐量降低的可能病理机制。方法选择年龄3月左右、体质量210～240g健康SD大鼠20只进行实验,雌雄各半,实验组14只(E组,n=14),对照组6只(N组,n=6)。E组以1g/kg体质量优甲乐灌胃,N组以相应剂量单纯生理盐水灌胃,1次/d,连续2周后取胰腺和肝脏标本进行实验。采用免疫组织化学观察胰腺β细胞caspase-3、Bcl-2,肝细胞PPARγ、GLUT2;脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)观察胰腺β细胞凋亡核甘酸。结果E组caspase-3、TUNEL阳性率明显高于N组,在α=0.05水平上较N组差异有统计学意义(P<0.01);E组Bcl-2表达阳性率明显低于N组,在α=0.05水平上较N组差异有统计学意义(P<0.01)。E组大鼠肝细胞PPARγ明显低于N组,在α=0.05水平上有显著差异(P<0.01)。GIUT2表达明显高于N组,在α=0.05水平上有显著差异(P<0.01)。结论甲状腺素对在体大鼠胰岛细胞具有明显诱导凋亡作用,同时对大鼠肝细胞PPARγ和GLUT2表达影响显著,可能是甲状腺功能亢进时合并糖尿病及糖耐量异常重要病理机制。
Objective To debate the effect of thyroxin on the expression of apoptotic nucleotide of pancreatic ceils, caspase-3, Bcl-2, peroxisome proliferator-activated receptor gamma（PPARγ） and Glucose transporter2 （GluT2）in order to study the possible pathogenesy of hyperthyroidism with diabetes or impaired glucose tolerance of rat. Methods 20 healthy rats （ three months old, weight about 210 - 240 g, female and male in half） were selected. Experimental group （ E group, n = 14 ）, control group （ N group, n = 6 ）. E group was given Euthyrox （ 1 g/kg ） by intragastric administration once a day. N group was given saline by the same method once a day After continuous 2 weeks, the pancreas and liver were taken away for experiments. Immunohistochemistry was carried out to observe caspase-3 and Bcl-2 of pancreatic cells, and PPAR and GLUT2 of liver, the apoptofic nucleosides was observed by temainal UTP nick end labelling （TUNEL）, Results Positive rate of caspase-3 and TUNEL in E group is statistically higher than that of N group （P 〈 0.01 ）, Expression rate of Bcl-2 in E group is statistically lower than that of N group （P 〈 0.01 ）. The expression of PPARγ in E group is obviousely lower than that of N group with statistical significance（ P 〈 0.01 ）, The expresion of GIUT2 in E group is also obviously higher than that of N group with statistical significance （P 〈 0, 01 ）. Conclusion thyroxin not only had the significant role in inducing apoptosis of pancreatic cells,but also had obvious effect on the PPARγ and GLUT2 of rat liver cell, which maybe the important pathogenesy of hyperthyroidism with diabetes and and impaired glucose tolerance.
出处
《医学综述》
2008年第17期2694-2696,共3页
Medical Recapitulate
