H1-histaminergic activation stimulates phosphatidylinositol labeling in rabbit aorta

Histamine and 2-(2-aminoethyl)-thiazole induced dose-dependent increases in the labeling of phosphatidylinositol in rabbit aorta whereas impromidine was without effect. The effect of histamine was inhibited by antihistamines with the following order of potency: mepyramine greater than or equal to pyrilamine much greater than cimetidine. The data indicate that H1-histaminergic activation stimulates phosphatidylinositol labeling in rabbit aorta and suggest the involvement of a calcium-signaling process in the action of H1-histaminergic receptors.