Histamine stimulates inositol phosphate accumulation via the H1-receptor in cultured human endothelial cells.
The effects of histamine on [3H]inositol phosphate ([3H]IP) accumulation was examined in the presence of lithium in [3H]inositol-prelabelled human umbilical vein endothelial cells. Histamine stimulated total [3H]IP formation in a dose-dependent manner with a half-maximal value (EC50) of around 1-2 X 10(-6) M. Mepyramine, but not cimetidine, completely abolished the histamine response indicating that activation of phosphoinositide hydrolysis is mediated via H1-receptors. These data are the first to suggest that activation of inositol lipid hydrolysis is the underlying transmembrane signalling mechanism histamine H1-receptors employ in mediating various endothelial cell functions.
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Parke-Davis Research Unit, Addenbrookes Hospital Site, Cambridge, U.K.
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D002478:Cells, Cultured; D002927:Cimetidine / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D007294:Inositol / Q000378:metabolism; D007295:Inositol Phosphates / Q000096:biosynthesis*; D007700:Kinetics; D011738:Pyrilamine / Q000494:pharmacology; D011968:Receptors, Histamine / Q000502:physiology*; D011969:Receptors, Histamine H1 / Q000502:physiology*; D013403:Sugar Phosphates / Q000096:biosynthesis*; D014471:Umbilical Veins / Q000378:metabolism
D007295:Inositol Phosphates; D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D013403:Sugar Phosphates; D007294:Inositol; D002927:Cimetidine; D006632:Histamine; D011738:Pyrilamine