Ⅰ_1-咪唑啉受体和α_2受体介导大鼠静脉注射莫索尼定的瞬时升压作用  

Moxonidine-induced transient pressor response is mediated by both I_1-imidazoline receptors andα_2-adrenoceptors in anesthetized spontaneously hypertensive rats

作　　者：马秀娟[1,2] 刘爱军[1] 沈甫明[1] 吴明月[1] 吴英良[3] 苏定冯[1] 

机构地区：[1]第二军医大学药学院药理学教研室 [2]沈阳药科大学药学院沈阳 110016 [3]沈阳药科大学药学院

出　　处：《第二军医大学学报》2007年第6期581-588,共8页Academic Journal of Second Military Medical University

基　　金：Supported by National High-tech R&D Program(863 Program,2006AA02Z-4Cl);National Natural Science Foundation of China(30330650).~~

摘　　要：目的:考察哪些受体参与了莫索尼定的瞬时升压作用。方法:雌性自发性高血压大鼠(SHR)采用乌拉坦麻醉。分别经静脉给予可乐定(3、10、30μg/kg)和莫索尼定(0.1、0.3、1.0 mg/kg),经侧脑室给予莫索尼定或经胃管给予莫索尼定(1.0、10.0 mg/kg).观察瞬时升压现象的发生情况;莫索尼定(0.3 mg/kg)静脉注射前预注射哌唑嚷(10.0μg/kg)、育亨宾(2.0 mg/kg)、酚妥拉明(0.2 mg/kg)、咪唑克生(1.0 mg/kg)或育亨宾+咪唑克生(2.0 mg/kg+1.0 mg/kg),观察莫索尼定瞬时升压作用的变化情况.确定α1受体、α2受体和Ⅰ_1-咪唑啉受体在莫索尼定瞬时升压中的作用。结果:在降压程度相当的情况下,静脉注射莫索尼定的瞬时升压作用比可乐定强大得多。莫索尼定的瞬时升压作用不受哌唑嗪的影响.但可被育亨宾、酚妥拉明或咪唑克生部分阻断,而被育亨宾+咪唑克生完全阻断。莫索尼定侧脑室和胃管给药不产生瞬时升压现象。结论:静脉注射莫索尼定引起的瞬时升压作用是由外周α2受体和Ⅰ_1-咪唑啉受体共同介导的。Objective： Clonidine, by activating peripheral α-adrenoceptors, produces transient pressor response after i. v.injection in anesthetized animals. Moxonidine, with at least 40 fold higher affinity to I1-imidazoline receptors than to α2-adreno-ceptors, produces also a transient pressor response. This work was designed to investigate whether I1-imidazoline receptors areinvolved in this pressor effect of moxonidine. Methods： Female spontaneously hypertensive rats （SHRs, aged 14-16 weeks）were anesthetized with urethane. To observe the transient pressor responses, moxonidine O.1, O.3, 1.0 mg/kg （intravenous,i. v. ）, 2.0μg （intracerebroventricular, i. c. v. ） and 1.0, 10.0 mg/kg （intragastric, i. g. ） were administrated in differentgroups of rats. To evaluate the roles of αl-adrenoceptors, α2 adrenoceptors and I1-imidazoline receptors in the transient pressor responses to moxonidine, prazosin （10.0μg/kg）, yohimbine （2.0 mg/kg）, phentolamine （0.2 mg/kg）, idazoxan （1.0 mg/kg） or yohimbine ＋ idazoxan （2.0 mg/kg ＋ 1.0 mg/kg） were intravenously given to the animals before moxonidine O. 3 mg/kg （i. v.）. Results： It was found that i. v. moxonidine produced a greater pressor response than clonidine when producing a similar reduction of blood pressure. This effect of moxonidine was not influenced by prazosin, but was partly inhibited by yohimbine, phentolamine or idazoxan, and completely blocked by the combination of yohimbine and idzaxon. Neither i. c. v. injection nor i.g. administration of moxonidine induced transient pressor responses. Conclusion： The transient pressor response of i. v. mox-onidine is mediated by both peripheral I1-imidazoline receptors and a2-adrenoceptors.

关 键 词：莫索尼定 可乐定 咪唑啉 高血压 血压 

分 类 号：R972.4[医药卫生—药品]