摘要
目的:探讨长期糖尿病大鼠心脏肾上腺素受体(AR)的改变及其与心功能变化之间的关系。方法:采用链脲佐菌素(STZ)注射造成胰岛素依赖性糖尿病大鼠模型,放射配体结合实验和离体左心房收缩功能实验等方法观察心脏AR及功能的改变。结果:与同龄对照大鼠相比,糖尿病大鼠心脏β-AR的最大结合容量(Bmax)下降34%(P<0.05),KD值不变;心脏α1-AR Bmax无显著改变。糖尿病大鼠左心房β-AR介导的最大收缩反应(Rmax)较对照组下降64%(P<0.05);α1-AR介导的最大收缩反应增加36 %(P<0.05),pD2值不变。结论:长期糖尿病大鼠心脏β-AR介导的最大收缩反应降低,其可能与β-AR数量减少有关。α1-AR介导的最大收缩反应代偿性增强,其可能与受体后信号转导效应增强有关。
Objective: To study the changes of cardiac adrenoceptor (AR) and its relation with cardiac function in long-term diabetic rats. Methods: The model of diabetic rats was induced by streptozotocin (STZ), and the levels of cardiac AR (β-AR and/or α1-AR) and cardiac function were detected by radioligand binding assays and functional determination of isolated left atria. Results: Compared with the control, the β-AR density (Bmax) was decreased by 34 % (P〈0.05) and the KD value was not changed in diabetic rats, then the Bmax of α1-AR was not altered significantly (P〉0.05). The maximal positive inotropic response (Rmax) induced by isoproterenol in left atria of rat was decreased by 64 % (P〈0.05). Rmax mediated α1-AR was increased by 36 % (P〈0.05), and pD2 value was not altered in isolated elective field driven left atria of diabetic rats. Conclusion: The results suggested that the cardiac Rmax of left atria was decreased in diabetic rat. This may be associated with the decreased Bmax of β-AR. That the Rmax compensatiom mediated by cardiac α1-AR increased in diabetic rat may be associated with the enhancement of post-receptor signal transduction.
出处
《现代生物医学进展》
CAS
2009年第3期452-454,共3页
Progress in Modern Biomedicine
基金
国家自然科学基金资助项目(30572073)
江苏省自然科学基金项目(DK2005428)
江苏省卫生厅重大项目K200402)
江苏省医学重点人才(RC2007024)