INTERACTION OF HISTAMINE H1‐ AND H2‐RECEPTOR ANTAGONISTS WITH HISTAMINE UPTAKE AND METABOLISM BY GUINEA‐PIG ISOLATED ATRIUM AND MOUSE NEOPLASTIC MAST CELLS in vitro

Abstract

1 Burimamide, metiamide, chlorpheniramine, triprolidine and cocaine, were tested as inhibitors of histamine uptake and metabolism in the guinea-pig atrium and in mouse neoplastic mast cells. 2 Cocaine did not affect the uptake and metabolism of histamine, either in the atrium or in the mast cells. All the antihistamines tested blocked the uptake and metabolism of histamine in both preparations. The order of potency was burimamide > chlorpheniramine > triprolidine > metiamide in the atrium; and burimamide > metiamide > triprolidine > chlorpheniramine, in the mast cells. 3 Comparison of the present results with the antihistamine activity of these blocking agents suggests that no correlation exists between the receptor blocking activity and the ability of these substances to act as inhibitors of histamine uptake and metabolism.