Murai T, Sanai K, Miyao Y, Kanai T
Kaken Pharmaceutical Co., Ltd., Central Research Laboratories, Tokyo, Japan.
J Hypertens Suppl. 1988 Dec;6(2):S55-8.
We studied the effects of urapidil on bronchospasm, myocardial hypoxia and postural hypotension in experimental animals. Urapidil dose-dependently inhibited bronchospasm induced by histamine in anaesthetized guinea pigs and the contraction of isolated trachea induced by noradrenaline or phenylephrine. Urapidil markedly delayed the appearance of severe dyspnoea induced by histamine aerosol in guinea pigs. Further, urapidil inhibited isoproterenol-induced ST depression in rats and inhibited histamine-induced ST depression in rabbits. The postural hypotension induced by prazosin was greater than that induced by urapidil in equihypotensive doses in conscious rabbits. Urapidil induced a lesser alpha-blockade in the vein than in the artery compared with prazosin. These combined properties of urapidil suggest that the drug is worth investigation in hypertensive patients with bronchial asthma or ischaemic heart disease.
我们研究了乌拉地尔对实验动物支气管痉挛、心肌缺氧和体位性低血压的影响。乌拉地尔剂量依赖性地抑制麻醉豚鼠体内组胺诱导的支气管痉挛以及去甲肾上腺素或去氧肾上腺素诱导的离体气管收缩。乌拉地尔显著延迟了豚鼠体内组胺气雾剂诱导的严重呼吸困难的出现。此外，乌拉地尔抑制大鼠异丙肾上腺素诱导的ST段压低，并抑制家兔组胺诱导的ST段压低。在清醒家兔中，等降压剂量下，哌唑嗪诱导的体位性低血压比乌拉地尔诱导的更明显。与哌唑嗪相比，乌拉地尔在静脉中诱导的α受体阻滞作用比在动脉中更小。乌拉地尔的这些综合特性表明，该药物值得在患有支气管哮喘或缺血性心脏病的高血压患者中进行研究。
