糖尿病大鼠胰腺中蛋白激酶B表达和细胞凋亡的变化

Expression of PKB and apoptosis in pancreas of diabetic rats

目的:探讨糖尿病大鼠胰腺中磷酸化蛋白激酶B表达及胰腺β细胞增殖与凋亡的变化。方法:将糖尿病大鼠腹腔内注射链脲佐菌素,实验中监测血糖,用免疫组织化学染色法观察胰腺中胰岛素、磷酸化蛋白激酶B的表达,以及胰腺β细胞的增生及凋亡情况。结果:糖尿病大鼠胰腺中胰岛素、磷酸化蛋白激酶B的表达水平均降低(P<0.01),糖尿病组β细胞凋亡率明显高于对照组(P<0.01),2组大鼠胰腺β细胞均无明显增生。结论:磷酸化蛋白激酶B在糖尿病大鼠胰腺中的表达水平下降,蛋白激酶B介导的信号传导系统可能抑制胰腺β细胞的凋亡。

Objective To explore the changes of expression of phosphorylation PKB in pancreas of experimental diabetic rats, and the changes of the proliferation and apoptosis of pancreas .β cell. Methods The diabetic rats were duplicated with streptozotocin intraperitoneally. The changes of blood glucose were measured. Immunostaining with the marker of insulin and phosphorylation PKB were examined. The proliferation of islet cells was immunostained with Ki-67. The apoptosis of islet cells was assessed with dUTP nick end labeling method（TUNEL）. Results The expressions of insulin and phosphorylation PKB decreased in experimental group （P〈0.01）. The percentage of β cell apoptosis of experimental group was significantly higher than that of control group （P〈0.01）. There was no significant proliferation of β cell in two groups. Conclusion The expression of phosphorylation PKB decreases in diabetic rats, and the signal pathway induced by PKB may inhibit the apoptosis of β cell.