胰高血糖素调控肝脏、肾脏及肠道糖异生的作用  

Regulation of gluconeogenesis in liver,kidney and intestine by glucagon

作　　者：苏琬真 李爱云 张燕[1] 张翼超 焦向英[1] SU Wan-zhen;LI Ai-yun;ZHANG Yan;ZHANG Yi-chao;JIAO Xiang-ying(Department of Physiology,Shanxi Medical University,Key Laboratory of Cellular Physiology,Ministry of Education,Taiyuan 030001,China)

机构地区：[1]山西医科大学生理学系细胞生理学教育部重点实验室,山西太原030001

出　　处：《中国药理学通报》2023年第7期1332-1338,共7页Chinese Pharmacological Bulletin

基　　金：山西省基础研究计划青年科学研究项目(No.202103021223212);山西医科大学校级博士启动基金项目(No.XD2012)。

摘　　要：目的 探究不同空腹时间段胰高血糖素对肝脏、肾脏和肠道糖异生的调节作用及机制。方法 将8周龄C57BL/6J雄性小鼠随机分为6组:空白对照组、空白对照+胰高血糖素组、禁食18 h组、禁食18 h+胰高血糖素组、禁食36 h组、禁食36 h+胰高血糖素组。采用葡萄糖、甘油三酯及游离脂肪酸试剂盒检测胰高血糖素刺激下不同禁食时间段的小鼠血清中三者的含量变化;肝/肌糖原试剂盒及PAS染色观察肝脏中糖原含量的变化;RT-PCR法观察胰高血糖素在不同禁食时间下对肝脏、肾脏和肠道中PGC-1α、G6Pase及PEPCK基因表达的影响;Western blot法检测肝脏、肾脏和肠道中PGC-1α、G6Pase、PEPCK、p-PKA、PKA、p-CREB及CREB蛋白表达的变化。结果 (1)胰高血糖素升高空腹血清葡萄糖水平、降低血清甘油三酯和游离脂肪酸水平,并减少肝脏糖原含量;(2)胰高血糖素通过增加PGC-1α表达而促进糖异生,且在胰高血糖素的刺激下,在禁食18 h和36 h时,肝脏PGC-1α基因和蛋白表达均明显增加,而在禁食18 h时,肾脏PGC-1α基因和蛋白表达增加,在禁食36 h时,肠道PGC-1α基因和蛋白表达明显增加;(3)胰高血糖素促进禁食后肝脏、肾脏和肠道中糖异生相关酶G6Pase、PEPCK的基因和蛋白表达;(4)胰高血糖素增加肝脏中p-PKA/PKA及p-CREB/CREB水平。结论 胰高血糖素对肝脏、肾脏和肠道糖异生反应表现出时间差异性,并通过增加PGC-1α基因和蛋白表达而促进糖异生关键酶G6Pase和PEPCK基因和蛋白表达,从而增加空腹血糖水平。此外,胰高血糖素通过PKA/CREB信号通路促进肝脏糖异生。Aim To investigate the regulatory effect of glucagon on gluconeogenesis in liver,kidney and intestine during different fasting periods and the underlying mechanism.Methods The 8-week-old male C57BL/6J mice were randomly divided into six groups(n=6):control group,control+glucagon group,fasting 18 h group,fasting 18 h+glucagon group,fasting 36 h group,and fasting 36 h+glucagon group.Glucose,triglyceride(TG)and free fatty acids(FFAs)kits were used to detect their serum contents in mouse intraperitoneal injection of glucagon at different fasting time points.Besides,liver/muscle glycogen assay kit and PAS staining were used to detect the glycogen contents in liver tissue.RT-PCR method was used to observe the effects of glucagon on the gene expressions of peroxisome proliferators-activated receptorγcoactivator lα(PGC-1α),glucose-6-phosphatase(G6Pase)and phosphoenol pyruvate carboxykinase 1(PEPCK)in liver,kidney and intestine of mice at different fasting time.Western blot was employed to detect the protein expressions of PGC-1α,G6Pase,PEPCK,phosphorylase protein kinase A(p-PKA),prot1ein kinase A(PKA),phosphorylase cAMp-response element binding protein(p-CREB)and cAMp-response element binding protein(CREB)in liver,kidney and intestine of mice were.Results(1)Glucagon increased the serum glucose level,reduced serum TG and FFAs levels,and reduced the hepatic glycogen content.(2)Glucagon promoted gluconeogenesis via upregulation of PGC-1α.On the stimulation of glucagon,PGC-1αgene and protein expressions in liver were significantly raised by glucagon when the mice were fasted 18 h and 36 h,while the gene and protein expressions of PGC-1αin kidney were obviously up-regulated by glucagon after fasting 18 h.However,PGC-1αgene and protein expressions in intestine were significantly elevated by glucagon at 36 h after fasting.(3)Glucagon induced gene and protein expressions of gluconeogenesis-related enzymes G6Pase and PEPCK in liver,kidney and intestine after fasting.(4)Glucagon upregulated p-PKA/PKA and p-CREB/CREB in liv

关 键 词：糖尿病 胰高血糖素 糖异生 肝脏 肾脏 肠道 

分 类 号：R-332[医药卫生] R322.45R322.47R322.61R587.1R977.15