左旋四氢巴马汀对α_1和α_2肾上腺素受体的作用  

THE ACTION OF I-TETRAHYDROPALMATINE ON_(α_1) AND α_2 ADRENOCEPTORS

作　　者：姚兵[1] 卞春甫[1] 许鹏程[1] 郑加麟[1] 

机构地区：[1]徐州医学院药理学教研室

出　　处：《徐州医学院学报》1991年第1期20-24,共5页Acta Academiae Medicinae Xuzhou

摘　　要：左旋四氢巴马汀(I-THP)选择性地抑制~8H-prazosin和~3H-clo-nidine与大鼠脑细胞膜上α_1和α_2肾上腺素受体的结合,与α_1、α_2受体的亲和力(Pki)分别为5.84和5.87。其拮抗苯肾上腺素收缩大鼠离体主动脉条作用PA_2值为5.59,它使利血平化大鼠出现升压效应,并为育亨宾所阻滞。大剂量I-THP能拮抗可乐定的升压作用,表明I-THP有阻滞α_1受体的作用,小剂量时能激动突触前膜α_2受体,大剂量亦能阻滞突触后的α_2受体。1-THP selectively inhibted the specific binding of 3H-Prazosine and 3H-clonidine to α1 and α2 adrenoceptors of rat cerebral cortex cell membrane with affinity ( PKi ) of 5.84 and 5.87 respectively. The cumulative dose-effect curves for PhenylePhrine were shifted to the right Parallelly by prazosin (4.3, 8.6, 12.9, 17.2nM)and 1-THP (4.68, 9.36, 14.0, 23.4uM ) in isolated rat aortic strips with no change in the maximal response. The PA2 values of 1-THP and Prazosin were 5.59 and 8.86 respectively. 1-THP 2.5 mg/kg iv decreased the blood Prassure in normal rats, but increased the blood Pressure in reserPinized rats, and this Pressor action was antagonized by yohimbine 3.56 mg/kg iv. 1-THP 20 mg/kg iv inhibiteb the Pressor action of clonidine. These results indicate that 1-THP blocks α1 adrenoceptors, small-dose 1-THP stimulates Presynaptic ct2 adrenoceptors, and large-dose 1 -THP also blocks PostsynaPtic α2 adrenoceptors.

关 键 词：1-THP Α-受体 血压 

分 类 号：R966[医药卫生—药理学]