Histamine-induced modulation of vascular tone in the isolated chicken basilar artery: a possible involvement of endothelium.
We investigated the histamine responsiveness of basilar arterial rings isolated from chicken. We also examined whether endothelial cells were involved in the histamine responsiveness and in resting vascular tone. Histamine induced concentration-dependent relaxations under condition of precontraction by 5-hydroxytryptamine. The concentration-response curve for histamine was shifted to the right by diphenhydramine (a H(1) receptor antagonist), cimetidine (a H(2) receptor antagonist) and Nomega-nitro-L-arginine (L-NNA, a nitric oxide synthase inhibitor); however, indomethacin (a cyclooxygenase inhibitor) had no significant effect on it. Treatment with L-NNA shifted the concentration-response curve of histamine to the right in the presence of cimetidine, but not in the presence of diphenhydramine. Treatment with cimetidine shifted the concentration-response curve of histamine to the right in the presence of diphenhydramine. L-NNA induced a contraction but indomethacin had no effect on the resting vascular tone. These results suggest that histamine-induced relaxation is mediated via activation of H(1) receptors located on endothelial cells and H(2) receptors located on smooth muscle cells. The main relaxing factor released from endothelial cells is probably nitric oxide. The resting vascular tone was modulated by spontaneously released nitric oxide, but not by prostaglandins or thromboxane A(2).
Okuno
Tadatsune
T
Department of Veterinary Pharmacology, Faculty of Agriculture, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890-0065, Japan.
Yabuki
Akira
A
Shiraishi
Mitsuya
M
Obi
Takeshi
T
Miyamoto
Atsushi
A
D000818:Animals; D001488:Basilar Artery / Q000187:drug effects / Q000378:metabolism*; D002645:Chickens; D002927:Cimetidine / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004155:Diphenhydramine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006632:Histamine / Q000378:metabolism*; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D019335:Nitroarginine / Q000494:pharmacology; D011969:Receptors, Histamine H1 / Q000187:drug effects / Q000378:metabolism; D011970:Receptors, Histamine H2 / Q000187:drug effects / Q000378:metabolism; D012701:Serotonin / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000378:metabolism*
D016861:Cyclooxygenase Inhibitors; D004791:Enzyme Inhibitors; D006634:Histamine H1 Antagonists; D006635:Histamine H2 Antagonists; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D019335:Nitroarginine; D009569:Nitric Oxide; D012701:Serotonin; D002927:Cimetidine; D006632:Histamine; D004155:Diphenhydramine; D019001:Nitric Oxide Synthase; D007213:Indomethacin