Histamine H2-receptors in the sheep bronchus and cat trachea: the action of burimamide.

Histamine-induced relaxation of the sheep bronchus was antagonized by burimamide but not by mepyramine, indicating the presence of H(2)-receptors. Mepyramine or burimamide alone produced partial antagonism of histamine-induced relaxation of the cat trachea. Both inhibitors added simultaneously effectively abolished the histamine response, suggesting that both H(1)- and H(2)-receptors are active in relaxing the cat trachea.