Saari J T
Pharmacology. 1986;32(2):80-9. doi: 10.1159/000138155.
Successive applications of histamine in the isolated, perfused rabbit heart revealed a transient constriction of coronary vasculature. The mechanism of this vasoconstriction, in particular its tachyphylactic nature, was the subject of this study. Diphenhydramine, perfused during one of the applications of histamine, blocked the vasoconstriction, indicating an H1-receptor-mediated response. Cimetidine, perfused during one of the applications of histamine, enhanced the vasoconstriction, indicating that H2-receptors mediate an inhibition of vasoconstriction. Cimetidine perfused during all applications of histamine reduced, and in some cases eliminated, the apparent tachyphylaxis, implying that the waning vasoconstrictor response normally seen with histamine was due to a gradually increasing H2-receptor-mediated inhibition.
在离体灌注兔心脏中连续应用组胺，可观察到冠状动脉血管出现短暂收缩。本研究的主题是这种血管收缩的机制，尤其是其快速耐受性的本质。在其中一次应用组胺期间灌注苯海拉明，可阻断血管收缩，表明这是一种由H1受体介导的反应。在其中一次应用组胺期间灌注西咪替丁，增强了血管收缩，表明H2受体介导血管收缩的抑制作用。在所有组胺应用期间都灌注西咪替丁，可减轻并在某些情况下消除明显的快速耐受性，这意味着通常所见的组胺血管收缩反应减弱是由于H2受体介导的抑制作用逐渐增强所致。
