尾端延髓腹外侧区咪唑啉受体在可乐定中枢降压效应中的作用  

Contribution of imidazoline receptors in caudal ventrolateral medulla to central depressor effect of clonidine

作　　者：陈文生 史胜[2] 王伟忠[3] 袁文俊[3] 

机构地区：[1]杭州市邮电医院脑外科,杭州310005 [2]解放军第85医院眼科,上海200052 [3]第二军医大学基础医学部生理学教研室,上海200433

出　　处：《第二军医大学学报》2004年第8期835-837,共3页Academic Journal of Second Military Medical University

基　　金：国家重点基础研究规划("973"计划)课题(G2000056905).

摘　　要：目的:探讨大鼠尾端延髓腹外侧区(CVLM)在介导可乐定降压机制中的作用。方法:氨基甲酸乙酯麻醉SD大鼠20只,体质量250-350 g,应用微量注射和动脉插管记录血压等方法观察CVLM给予咪唑啉1和α2-肾上腺素受体阻断剂对可乐定导致的心血管活动的影响。结果:双侧CVLM预先微量注射咪唑啉1和α2-肾上腺素受体阻断剂idazoxan(5 nmol)不仅能降低平均动脉血压[(-17.3±6.9)mmHg,1 mmHg＝0.133 kPa,P<0.01]和心率[-23.9±3.6)次／min,P<0.01],而且能完全阻断静脉注射可乐定(10 μg／kg)导致的降压[(-29.5±6.1)vs(-1.4±2.3)mmHg,P<0.01]和降心率效应[(-30.8±6.7)vs(-3.0±4.6)次／min,P<0.01],而预先CVLM微量注射α2-肾上腺素受体阻断剂育亨宾(500 pmol)则不能影响可乐定导致的心血管效应。结论:CVLM咪唑啉受体1参与可乐定的中枢降压效应。Objective:To explore the roles of the caudal ventrolateral medulla(CVLM) in the central anti-hypertensive mechanism. Methods : In 20 urethane-anesthetized SD rats, the effects of I1-imidazoline receptor and α2-adrenceptor antagonists (microinjection into the CVLM) on the cardiovascular responses induced by intravenous clonidine were observed. Results: Prior bilateral microinjection of mixed antagonist idazoxan (I1-imidazoline receptor and a2-adrenceptor) into the CVLM not only decreased the mean arterial pressure [(-17. 3 ± 6. 9) mmHg, 1 mmHg = 0. 133 kPa, P<0. 01] and heart rate [( - 23. 9 ± 3. 6) beats/min, P<0. 01], but also completely blocked the depressor effect[( - 29. 5 ± 6. 1) vs ( -1. 4±2. 3) mmHg, P<0. 01] and bradycardiac effect[(- 30. 8 ± 6. 7) vs (-3. 0 ± 4. 6) beats/min, P<0. 01] of intravenous clonidine. Whereas, bilaterally injected α2-adrenceptor antagonist yohimbine did not alter the basal cardiovascular acitivities and cloni dine-induced cardiovascular responses. Conclusion: The I1-imidazoline receptors in the CVLM contribute to central anti-hypertension of clonidine.

关 键 词：咪唑啉1受体 可乐定 血压 尾端延髓腹外侧区 

分 类 号：R972.4[医药卫生—药品]