论文部分内容阅读
组胺有强的扩张血管作用,近期研究显示其对人体心脏有直接作用。正常人注射组胺的正性变力和变时性反应,是直接兴奋心肌组胺 H_2受体所致;周围血管丛中组胺 H_1和 H_2受体使血管扩张,反射性地增强了心脏效应。心血管组胺 H_2受体的生理作用未明,但其拮抗剂甲氰咪胍和呋喃硝胺(ranifidine)可能产生不良的血液动力学作用。甲氰咪胍治疗可致心动过缓已有报道,提示H_2受体拮抗剂可能减弱胃肠出血的变时性反应。某些患者在甲氰咪胍治疗前血液动力学不稳定,但也有患者选择性再用本药能重新引起心动过缓。近有报告呋喃
Histamine has a strong dilation of blood vessels, recent studies have shown that it has a direct effect on the human heart. Normal human histamine histamine positive variability and chronotropic response, is directly excited by histamine H_2 receptors; histamine H_1 and H_2 receptors in the surrounding vascular plexus blood vessels dilate, reflexively enhance the heart effect . The physiological role of cardiovascular histamine H 2 receptors is unknown, but their antagonists cimetidine and ranifidine may have adverse hemodynamic effects. Cimetidine treatment can cause bradycardia has been reported, suggesting that H2 receptor antagonist may reduce the gastrointestinal bleeding time-dependent response. Some patients have hemodynamic instability before cimetidine treatment, but some patients may re-induce bradycardia with this drug. Nearly reports furan