McNeill J H, Verma S C, Tenner T E
Adv Myocardiol. 1980;1:209-16.
Histamine can produce inotropic and chronotropic responses in both guinea pig and rabbit heart. In the guinea pig the responses are mediated primarily through stimulation of H2 receptors with H1 receptors being found mainly in left atria. In the rabbit H1 receptors predominate; H2 receptors are found only in right atria and are partially responsible for the chronotropic effect. H2 receptors are always associated with cyclic AMP, whereas H1 receptors are not. H2-histamine receptors and beta-adrenergic receptors have a number of properties in common. Stimulation of either receptor results in positive inotropic and chronotropic effects and increases in cyclic AMP and phosphorylase a. H2 and beta-adrenergic agonists will also both restore the action potential in K+-depolarized cardiac muscle. H1 and alpha-agonists, on the other hand, will also produce an inotropic effect. The effect is not dependent on cyclic AMP and can only be demonstrated under certain conditions. Neither agonist will restore the action potential in depolarized cardiac tissue. It is concluded that, although H2 and beta-agonists and H1 and alpha-agonists may have a common mechanism of action, the two groups of drugs (H2, beta versus H1, alpha) differ from each other with regard to mechanism.
组胺可使豚鼠和兔的心脏产生变力性和变时性反应。在豚鼠中，这些反应主要通过刺激H2受体介导，而H1受体主要存在于左心房。在兔中，H1受体占主导；H2受体仅存在于右心房，且对变时性效应有部分作用。H2受体总是与环磷酸腺苷（cAMP）相关联，而H1受体则不然。H2 - 组胺受体和β - 肾上腺素能受体有许多共同特性。刺激任一受体都会产生正性变力性和变时性效应，并使环磷酸腺苷和磷酸化酶a增加。H2和β - 肾上腺素能激动剂也都能恢复钾离子去极化心肌中的动作电位。另一方面，H1和α - 激动剂也会产生变力性效应。该效应不依赖于环磷酸腺苷，且仅在某些条件下才能表现出来。两种激动剂都不能恢复去极化心脏组织中的动作电位。结论是，尽管H2和β - 激动剂以及H1和α - 激动剂可能有共同的作用机制，但两组药物（H2、β与H1、α）在作用机制方面彼此不同。
