摘要
目的观察长期糖尿病大鼠心脏α1肾上腺素能受体(α1-AR)及其三种亚型的改变。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α1-AR及其三种亚型的改变。结果糖尿病大鼠与同龄对照大鼠相比,心脏α1-AR最大结合容量(Bmax)无显著差异,但α1B-AR减少,α1D-AR增加。糖尿病大鼠左心房α1-AR介导的最大收缩反应较对照组增加36%(P<0.05),pD2值不变。α1-AR亚型三种不同选择性拮抗剂5-MU、spiperon和BMY7378拮抗NE正性变力效应的pA2值不变。结论提示长期糖尿病大鼠心脏α1-AR介导的最大收缩反应增强,其主要与受体后信号转导效应增强有关,其中以α1B-AR尤为显著。
Objective To observe the changes of cardiac α1-adrenoceptor（α1-AR） and its subtypes in strepotozocin- induced diabetic rats. Methods The changes were studied by radioligand binding assays and functional determination of isolated left atria. Results Compared with the age matched normal rats, the total amount of cardiac α1-AR was not altered, α1B-AR was decreased and α1D-AR was increased in the diabetic rats. α1-AR mediated maximal positive inotropic response was increased by 36% （P 〈 0.05）, and pD2 value did not change in isolated elective field driven left atria of diabetic rats. The pA2 values of selective antagonists for three α1-AR subtypes against the norepinephrine-induced positive inotropic response did not change significantly. Conclusion These findings suggest that cardiac α1-AR, especially α1Bsubtype, mediated positive inotropic response of the long-term diabetic rats is increased, which may be associated with the enhancement of post-receptor signal transduction.
出处
《中国微循环》
2009年第3期157-160,共4页
Journal of Chinese Microcirculation
基金
国家自然科学基金资助项目(No.30572073)
江苏省自然科学基金资助项目(BK2005428)
江苏省"六大人才高峰"第三批资助项目(C类)江苏省医学重点人才(RC2007024)
