促甲状腺素释放激素增强失血性休克大鼠心脏受体功能及其机理  

TRH potentiates cardiac adrenoceptor induced response and its mechanism

作　　者：刘良明[1] 胡德耀[1] 陈惠孙[1] 卢儒权[1] 李金鸣[1] 张克义[1] 郝丽英[1] 王玉萍[1] 

机构地区：[1]重庆第三军医大学野战外科研究所,中国医科大学药理教研室

出　　处：《中国病理生理杂志》1995年第5期483-487,共5页Chinese Journal of Pathophysiology

摘　　要：本文用失血性休克大鼠离体左房观察了促甲状腺素释放激素（ｔｈｙｒｏｔｒｏｐｉｎｒｅｌｅｎｓｉｎｇｈｏｒ－ｍｏｒｅ，ＴＲＨ）对肾上腺素能和多巴胺受体激动剂正性肌力作用的影响，用全细胞记录式膜片钳制技术研究了ＴＲＨ对豚鼠单一心肌细胞慢钙内流的作用及对肾上腺素能和多巴胺受体激动剂促钙内流作用的影响。结果显示，ＴＲＨ本身对失血性休克大鼠离体左房仅有轻微的正性肌力作用，但却可增强异丙肾上腺素和多巴胺的正性肌力作用，但不增强苯肾上腺素的正性肌力作用。表明ＴＲＨ对休克大鼠心脏β－肾上腺素能和多巴胺受体具有一定的增敏作用。ＴＲＨ可延长豚鼠单一心肌细胞的钙通道开放时间，增强异丙肾上腺素和多巴胺的促钙内流作用，这可能是ＴＲＨ增敏心脏β和ＤＡ受体，增加其受体激动剂正性肌力作用的重要原因。Effects of thyrotropin releasing hormone(TRH )on the responsivenessof isolated left atria of hemorrhagic shock rats to adrenergic agonists,and the effects ofadrenergic agonists to increase calcium current(Ica)induced by TRH in single cardiaccells of guinea-pig with patch clamp technique(whole cell recording ) were observed. The results indicated that TRH could only increase the cardiac contractility slightly,but it could potentiate the positive inotropic actions of isoprenaline( ISO)and d dopamine(DA)remarkably, while it did not potentiate the effect of phenylephrine(Phe ).TRHmight prolong the open duration of calcium channel ( Dca)and strengthen calcium ionicinward effects of ISO and DA. It is suggested that TRH might sensitize βand DA re-ceptor in the rat hearts during hemorrhagic shock and raise their responsiveness to theiragonists.TRH prolonged the Dca and increased the calcium inward actions of ISO andDA. It may be the mechanism by which TRH sensitizes βand DA receptors,and poten-tiates the positive inotropic actions of their agonists.

关 键 词：休克 失血性休克 心脏 肾上腺素能 离子通道 TRH 

分 类 号：R605.971[医药卫生—急诊医学]