糖尿病小鼠胸主动脉环对血管收缩剂和内皮依赖性舒张剂反应的变化

目的：探讨糖尿病（DM）小鼠在不同时期离体胸主动脉环对血管收缩剂和内皮依赖性舒张剂反应的变化。 方法： 用腹腔注射链脲佐菌素（STZ）40 mg/kg诱导C57BL/6J小鼠产生糖尿病，在17、22和28周分批处死糖尿病和同年龄对照（control）组小鼠，测定其离体胸主动脉环对血管收缩剂：苯肾上腺素（PE）、60 mmol/L KCl的反应及对内皮依赖性舒张剂乙酰胆碱（ACh）的反应。 结果： DM组小鼠2周后空腹血糖≥11.1 mol/L并在整个实验过程中维持这一水平，显著高于control组，而体重显著低于control组；17、22和28周DM组胸主动脉环对PE的反应性分别高于、接近、高于control组，各时期对60 mmol/L KCl都表现高于control组；17、22和28周DM组胸主动脉环对ACh的反应性分别高于、接近、低于control组。 结论： DM组小鼠胸主动脉环对血管收缩剂的反应增强，而内皮功能先代偿性增强，然后降低，表现为内皮损伤。

Effects of vasoconstrictor and endothelium-dependent relaxationagent on thoracic aortic rings of diabetes mice

AIM: To discuss the effects of vasoconstrictor and endothelium-dependent relaxation agent on the thoracic aortic rings in different stages of diabetes mellitus. METHODS: Streptozotocin (STZ, 40 mg/kg) was injected intraperitoneally to establish diabetic model in C57BL/6J mice. At the 17th, 22nd, 28th week, diabetic and age-matched control mice were sacrificed respectively and the effects of vasoconstrictors: phenylephrine (PE), 60 mmol/L KCl and endothelium-dependent relaxation agent respectively (ACh) were measured in two groups using thoracic aortic rings. RESULTS: The level of fasting plasma glucose concentration 2 weeks after STZ treatment increased higher (≥11.1 mol/L) in STZ-induced diabetic mice than that in age-matched controls, and maintained at this level in entire experiment course. On the contrary, the weight was decreased significantly. The responses of thoracic aortic rings in STZ-induced diabetic mice to PE were increased, unaltered and increased at the 17th, 22nd, 28th weeks, respectively compared to that in age-matched controls. The responses to 60 mmol/L KCl were also increased in all stages. While the responses to ACh were increased, unaltered and decreased at the 17th, 22nd, 28th weeks, respectively compared to that in age-matched controls. CONCLUSION: The responses of thoracic aortic rings to vasoconstrictor enhance in STZ-induced diabetic mice. However, the endothelial functions potentiate initially due to compensation, and then lower exhibiting endothelial damage.