目的:构建1型糖尿病(type 1 diabetes mellitus,T1DM)小鼠反复低血糖(recurrent hypoglycaemia,RH)模型,并探讨低血糖时其胰高血糖素样肽1(glucagon-like peptide-1,GLP-1)在肠道的表达及意义.方法:以链脲佐菌素诱导C57BL/6J小鼠,形成T1DM,在糖尿病第15天腹腔注射短效胰岛素,每3 d注射1次,连续5次降至低血糖,以构建T1DM-RH模型.建模期间记录小鼠体重、血糖水平及活动状态;ELISA检测模型鼠第5次降糖持续60 min后的血浆肾上腺素、胰高血糖素(glucagon,GCG)、生长抑素(somatostatin,SST)和GLP-1水平;免疫荧光检测模型鼠肠GLP-1和胰岛α、δ细胞激素的分泌变化;Western blot检测回肠和结肠的GLP-1及其受体GLP-1R、激素原转化酶1/3(prohormone convertases 1/3,PC1/3)蛋白的表达.结果:血糖、体重符合T1DM鼠标准.RH组连续降糖5次,每次血糖均降至(3.3±0.5)mmol/L,且持续时间>60 min,加之其血浆肾上腺素、血浆GCG水平及RH小鼠降糖期间行为改变,符合糖尿病小鼠RH和低血糖反调节障碍的建模标准.ELISA显示,与T1DM组相比,RH组血浆肾上腺素和GCG水平均下降(P<0.01),血浆SST和活性GLP-1水平显著升高(P<0.01);免疫荧光显示,与T1DM组相比,RH组肠GLP-1表达升高,胰岛SST分泌增多(P<0.01),GCG分泌减少(P<0.01);Western blot显示,与T1DM组相比,RH组肠活性GLP-1和GLP-1R明显升高(P<0.01).结论:TIDM-RH小鼠肠GLP-1表达升高,与低血糖反调节障碍的形成或加重密切相关.
AIM:To establish a model of recurrent hypoglycemia(RH)in mice with type 1 diabetes mellitus(T1DM)and to investigate the expression and effects of glucagon-like peptide-1(GLP-1)in the intestines of the model mice.METHODS:The T1DM model was established by induction with streptozotocin.Starting from the 15th day of T1DM,the mice in RH group were injected intraperitoneally with short-acting insulin,experiencing 1 episode of hyperin-sulinemic hypoglycemia every 3 days over 5 episodes,to establish the RH model in T1DM mice.Body weight,blood glu-cose,and activity status of the mice were recorded.Enzyme-linked immunosorbent assay(ELISA)was used to measure plasma adrenaline,glucagon(GCG),GLP-1,and somatostatin(SST)levels after the fifth episode of hypoglycemia for 60 min.Immunofluorescence staining was utilized to detect the expression of intestinal GLP-1 and hormone secretions from pancreatic α and δ cells in each group.Western blot was employed to detect protein expressions of GLP-1,GLP-1 receptor(GLP-1R),and prohormone convertase 1/3(PC1/3)in the intestine.RESULTS:Blood glucose and body weight met the standards for T1DM mice.During the 5 episodes of hypoglycemia,blood glucose levels in the RH group dropped to(3.3±0.5)mmol/L for more than 60 min during each episode of hypoglycemia,along with levels of plasma adrenaline and gluca-gon and the behavioral changes of RH mice during hypoglycemia,which met the modeling criteria of RH and impaired hy-poglycemic counterregulation in diabetic mice.ELISA detection showed that the plasma adrenaline and GCG levels were lower in RH group than those in T1DM group(P<0.01),while the plasma active GLP-1 and SST levels in mice were sig-nificantly higher in RH group(P<0.01).Immunofluorescence analysis showed that intestinal GLP-1 expression and pan-creatic SST secretion increased in RH group(P<0.01),while GCG secretion decreased(P<0.01).Western blot analysis showed that the levels of intestinal active GLP-1 and GLP-1R in RH group were significantly higher than those in T1DM group(P<0.01).CONCLUSION:Recurrent hypoglycemia in T1DM mice leads to increased intestinal GLP-1 expres-sion and secretion,which is closely related to the formation or aggravation of impaired hypoglycemic counterregulation.
靳方馨;赵晶晶;王岩;李敏讷;李如江;郭军堂
山东第二医科大学组织学与胚胎学教研室,山东省高校重点实验室,山东 潍坊 261053山东第二医科大学病理生理学教研室,山东 潍坊 261053
基础医学
1型糖尿病;低血糖反调节障碍;胰高血糖素样肽1;肠道;胰腺
type 1 diabetes mellitus;impaired hypoglycemic counterregulation;glucagon-like peptide-1;in-testine;pancreas
《中国病理生理杂志》 2024 (005)
890-898 / 9
国家自然科学基金面上项目(No.81471048)
10.3969/j.issn.1000-4718.2024.05.014
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