Rhaleb N E, Rouissi N, Drapeau G, Jukic D, Regoli D
Department of Pharmacology, Faculty of Medicine, University of Sherbrook, Qué., Canada.
Can J Physiol Pharmacol. 1991 Jul;69(7):938-43. doi: 10.1139/y91-142.
Bradykinin (BK) and related kinins are potent stimulants of the rabbit jugular vein, the hamster urinary bladder, and the guinea pig trachea. The characterization of kinin receptors in these tissues was made with agonists and antagonists. Results obtained with agonists indicate that bradykinin and kallidin are much more active than des-Arg9-BK and suggest the presence of B2 receptors in the three organs. Some new agonists were also tested and the BK analogue, [Hyp3,Tyr(Me)8]BK, was found to be a potent and selective stimulant of the three preparations, with pD2 values of 8.56, 8.00, and 8.39, respectively, but inactive on the rabbit aorta (a B1-receptor system). Contractile effects of kinins in the rabbit jugular vein and hamster urinary bladder were reduced or eliminated by B2-receptor antagonists but at different concentration levels; e.g., acetyl-D-Arg[Hyp3,D-Phe7]BK showed pA2 values of 7.78 on the rabbit jugular vein but only 5.72 on hamster urinary bladder. This compound contracted the guinea-pig trachea and was found to be inactive as an antagonist on this preparation. Contractions of the hamster urinary bladder and the guinea-pig trachea in response to bradykinin were markedly reduced or eliminated by indomethacin and by BW 755C, while those of the rabbit jugular vein were not modified. The present findings indicate that the myotropic effect of kinins on the rabbit jugular vein depends on the activation of B2 receptors and suggest that B2 receptors are largely responsible also for the response of the hamster urinary bladder. B2 receptors and (or) a nonreceptor mechanism appear to be involved in the stimulant effects of the kinin agonists and some antagonists in the guinea-pig trachea.
缓激肽（BK）及相关激肽是兔颈静脉、仓鼠膀胱和豚鼠气管的强效刺激剂。利用激动剂和拮抗剂对这些组织中的激肽受体进行了表征。激动剂实验结果表明，缓激肽和赖氨酰缓激肽的活性远高于去精氨酸9 - 缓激肽，提示这三种器官中存在B2受体。还测试了一些新型激动剂，发现BK类似物[Hyp3,Tyr(Me)8]BK是这三种标本的强效选择性刺激剂，其pD2值分别为8.56、8.00和8.39，但对兔主动脉（一种B1受体系统）无活性。B2受体拮抗剂可降低或消除激肽对兔颈静脉和仓鼠膀胱的收缩作用，但所需浓度不同；例如，乙酰 - D - 精氨酸[Hyp3,D - 苯丙氨酸7]BK对兔颈静脉的pA2值为7.78，但对仓鼠膀胱仅为5.72。该化合物可使豚鼠气管收缩，且在该标本上作为拮抗剂无活性。吲哚美辛和BW 755C可显著降低或消除缓激肽引起的仓鼠膀胱和豚鼠气管收缩，而兔颈静脉的收缩不受影响。目前的研究结果表明，激肽对兔颈静脉的肌性效应取决于B2受体的激活，提示B2受体在很大程度上也介导了仓鼠膀胱的反应。B2受体和（或）一种非受体机制似乎参与了激肽激动剂和一些拮抗剂对豚鼠气管的刺激作用。
