摘要
目的比较糖尿病与高血压糖尿病大鼠心脏α1肾上腺素受体(α1-AR)及其介导的功能变化。方法采用制糖尿病和高血压糖尿病大鼠的模型、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大鼠心脏α1-AR及其介导的功能变化。结果与同龄对照大鼠相比,糖尿病大鼠心脏α1-AR的最大结合容量(Bmax)无显著增加;高血压糖尿病大鼠心脏α1-AR的Bmax显著增加(P<0.05)。与对照大鼠相比,糖尿病大鼠左心房α1-AR介导的最大收缩反应(Rmax)无显著增加;高血压糖尿病大鼠左心房α1-AR介导的Rmax下降26%(P<0.05),pD2值不变。结论糖尿病时,大鼠心脏α1-AR数量及其介导的Rmax均无显著增加;而高血压糖尿病时,虽然大鼠心脏α1-AR数量代偿性增加,但其介导的Rmax降低,可能与α1-AR后信号转导效应减弱有关。
Objective To study the alterations of cardiac α1-adrenoceptor（α1-AR） and cardiac function in diabetic rats and hypertensive-diabetic rats. Methods The models of diabetic and hypertensive-diabetic rats were induced by streptozotocin （STZ）, and all the Works were studied by radioligand binding assays and functional determination of isolated left atria. Results Compared with control, the α1-AR density was not changed significantly in diabetic rats, then the α1-AR density was increased significantly （P 〈 0.05 ） in hypertensive-diabetic rats. In diabetic rats, the maximal positive inotropic response（Rmax） induced by isoproterenol in left atria of rat was not changed. In hypertensive-diabetic rats, the Rmax of left atria was decreased by 26% （ P 〈 0.05 ）, the pD2 value was not altered. Conclusions Both of cardiac α1-AR density and Rmax doesn＇ t change in diabetic rat. The cardiac α1-AR numbers increase compensatively in hypertensive-diabetic rat, but the Rmax of left atria decrease, which may be associated with the reduction of post-receptor signal transduction.
出处
《中华全科医学》
2008年第12期1213-1214,共2页
Chinese Journal of General Practice
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"六大人才高峰"第三批资助项目(C类)
