摘要
目的 探讨大鼠尾端延髓腹外侧区 (CVLM)咪唑啉 I受体 (I1R)和α2 肾上腺素受体 (α2 AR)在介导可乐定中枢降压机制中的作用。方法 在氨基甲酸乙酯麻醉SD大鼠中 ,观察CVLM内局部给予I1R和α2 AR阻断剂后对基础血压(BP)、心率 (HR)以及外周给予可乐定导致降压效应的变化。结果 双侧CVLM分别微量注射选择性α2 AR阻断剂育亨宾 (单侧剂量 5 0 0 pmol·L-1,10 0nl,n =8)或I1R和α2 AR混合性阻断剂idazoxan(单侧剂量 2nmol·L-1,10 0nl,n =10 )后不仅明显降低BP和HR(P <0 0 1) ,而且能明显减弱静脉给予可乐定 (5 μg·kg-1)导致的降压效应 (P <0 0 1) ,此外 ,idazoxan对可乐定降压效应的减弱作用高于育亨宾 (P <0 0 1)。结论 CVLM内I1R和α2
AIM To investigate the roles of the caudal ventrolateral medulla (CVLM) I 1 imidazoline receptors (I 1R) and α 2 adrenoceptors (α 2 AR) in cental depressor mechanism of clonidine. MEHTODS Theeffects of locally administrated antagonists of I 1R and α 2 AR within CVLM on the resting blood pressure (BP), heart rate (HR) and the depressor action of intravenously administrated clonidine were observed in urethane anesthetized SD rats. RESULTS Bilateral microinjection of either yohimbine (a selective antagonist of α 2 AR, 500 pmol·L -1 in 100 nl for each side, n =8) or idazoxan (a mixed antagonist of I 1R and α 2 AR, 2 nmol·L -1 in 100 nl for each side, n =10) not only produced significant ( P <0 01) decreases in both BP and HR, but also significantly ( P <0 01) attenuated clonidine induced depressor action. In addition, the attenuation of clonidine depressor action by idazoxan is more significant ( P <0 01) than by yohimbine. CONCLUSION Both I 1R and α 2 AR in the CVLM involved in maintaining the tonic cardiovascular activities and mediating the depressor action of clonidine.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2003年第1期26-29,共4页
Chinese Pharmacological Bulletin
基金
国家"973"计划资助项目 (NoG2 0 0 0 0 5 690 5 )
国家自然科学基金资助项目 (No 30 0 70 30 6)
