吡咯烷二硫代氨基甲酸酯对2型糖尿病大鼠肝糖原合成的影响

目的:探讨吡咯烷二硫代氨基甲酸酯(PDTC)对糖尿病大鼠肝糖原合成的影响及其机制。方法:雄性Wistar大鼠,随机分为2组:正常饮食组和高脂饮食组。喂养8周后,高脂饮食组大鼠腹腔注射单剂量链脲佐菌素(STZ)27 mg/kg复制2型糖尿病大鼠模型,2型糖尿病大鼠造模成功后随机分为3组:糖尿病模型组、PDTC治疗组和胰岛素治疗组。PDTC治疗组大鼠每天腹腔注射PDTC(50 mg/kg)1次;其它各组每天同一时间注射相同体积的生理盐水,胰岛素治疗组大鼠在处死前1 h腹腔注射胰岛素(1 U/kg)1次。治疗1周后尾静脉采血测定各组大鼠血糖水平,然后断头处死大鼠,测定肝组织中肝糖原的含量,采用Western blotting分析大鼠肝脏中蛋白激酶B(PKB/Akt)和糖原合成酶激酶-3β(GSK-3β)磷酸化水平的变化。结果:糖尿病模型组与正常饮食组大鼠相比血糖显著升高(P0.01);肝糖原含量明显减少(P0.01);肝脏中Akt及GSK-3β磷酸化水平明显降低(P0.01)。与糖尿病模型组大鼠相比,PDTC治疗组与胰岛素治疗组大鼠肝糖原合成均显著增加(P0.01);血糖均明显降低(P0.01);肝脏中Akt和GSK-3β磷酸化水平均明显增加(P0.01)。结论:PDTC可通过调控Akt/GSK-3β活性,增加肝糖原合成,降低血糖。

Effects of pyrrolidine dithiocarbamate on synthesis of hepatic glycogen in diabetic rats

AIM: To determine the effect of pyrrolidine dithiocarbamate on hepatic glycogen synthesis and its mechanism in diabetic rats. METHODS: Male Wistar rats were randomly divided into normal diet group and high-fat diet group. After 8 weeks of feeding, the rats in high-fat diet group were injected intraperitoneally with a single dose of streptozotocin (27 mg/kg) to induce type 2 diabetes. The diabetes rats were randomly divided into 3 groups: diabetes mellitus group (DM), PDTC-treated group (DM+PDTC) and insulin-treated group (DM+INS). The rats in PDTC-treated group were injected with PDTC (50 mg/kg) intraperitoneally daily. At the same time, the rats in normal diet group, DM group and insulin-treated group were injected with equivalent volume of saline in the same way. The rats in insulin-treated group were injected with insulin (1 U/kg) 1 h before killed. After the treatment was taken for 1 week, the levels of blood glucose were measured, then the animals in all groups were killed. The liver glycogen content was detected, and the levels of GSK-3β and Akt phosphorylation in the liver tissues were analyzed by Western blotting. RESULTS: The blood glucose level and liver glycogen content were significantly higher, and the levels of GSK-3β and Akt phosphorylation were lower in DM group than those in normal-diet group (P<0.01). Compared with DM group, the glycogen content, the phosphorylation of Akt and GSK-3β in the liver tissues in DM+PDTC group and DM+INS group increased significantly (P<0.01), and the blood glucose levels decreased (P<0.01). CONCLUSION: PDTC increases the synthesis of liver glycogen and decreases the level of blood glucose by regulating the activity of Akt and GSK-3β in the liver.