Effects of histamine agonists and antagonists on luminol-dependent chemiluminescence of granulocytes.
Histamine inhibited luminol-dependent chemiluminescence (CL) of granulocytes in a dose-dependent manner, with an ID50 of about 3 X 10(-5) M. Dimaprit, a selective H2-agonist, produced a histamine-like effect. Furthermore, cimetidine, ranitidine, and TZU 0460, which are selective H2-antagonists, but not mepyramine, a selective H1-antagonist, blocked the inhibitory effect of histamine on CL. Thus it may be concluded that the inhibitory effect of histamine is mediated via histamine H2-receptors. H1- and H2-antagonists per se, except at extremely high concentrations, had no effect on CL of granulocytes.
D002927:Cimetidine / Q000494:pharmacology; D017259:Dimaprit; D006098:Granulocytes / Q000187:drug effects / Q000502:physiology*; D006632:Histamine / Q000494:pharmacology*; D006633:Histamine Antagonists / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008165:Luminol / Q000494:pharmacology*; D011724:Pyridazines / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D011899:Ranitidine / Q000494:pharmacology; D013890:Thiourea / Q000494:pharmacology
D006633:Histamine Antagonists; D011724:Pyridazines; D011725:Pyridines; D008165:Luminol; D002927:Cimetidine; D006632:Histamine; D011899:Ranitidine; C006183:2-(2-aminoethyl)pyridine; D013890:Thiourea; D011738:Pyrilamine; D017259:Dimaprit