Dulabh R, Vickers M R
Agents Actions. 1978 Dec;8(6):559-65. doi: 10.1007/BF01998882.
Histamine has been shown to inhibit a variety of immune responses including the antigen-induced, IgE mediated, release of histamine from sensitized human leucocytes and from sensitized monkey and dog mast cells. The inhibitory action of histamine appears to be mediated by action at a histamine H2-receptor. In in vitro experiments the H2-receptor antagonist metiamide has been shown to block this histamine effect and it has been suggested that H2-receptor antagonists could intensify immediate hypersensitivity reactions in vivo. The effects of the H2-receptor antagonist metiamide and cimetidine have been studied in in vitro and in vivo models of anaphylaxis in the guinea-pig. The amount of extracellular histamine found after antigen challenge is greater when an H2-receptor antagonist is present during the incubation of mast cells with antigen. Bronchoconstriction induced by antigen in sensitized guinea-pig is exacerbated only by high doses of cimetidine. Possible explanations for the mechanism of action involved are discussed.
组胺已被证明可抑制多种免疫反应，包括抗原诱导的、IgE介导的、致敏人白细胞以及致敏猴和犬肥大细胞释放组胺。组胺的抑制作用似乎是通过作用于组胺H2受体介导的。在体外实验中，H2受体拮抗剂甲硫咪胺已被证明可阻断这种组胺效应，有人提出H2受体拮抗剂可能会在体内增强速发型超敏反应。在豚鼠过敏反应的体外和体内模型中研究了H2受体拮抗剂甲硫咪胺和西咪替丁的作用。当肥大细胞与抗原孵育期间存在H2受体拮抗剂时，抗原攻击后发现的细胞外组胺量更多。仅高剂量西咪替丁会加剧致敏豚鼠中抗原诱导的支气管收缩。文中讨论了所涉及作用机制的可能解释。
