Vascular studies with histamine in vitro.
In vitro studies to analyse the pharmacology of histamine-induced dilatation of resistance vessels in rat hindquarters have been made. Histamine caused dose-dependent dilatation of resistance vessels over the concentration range 10(-9) to 10)-6) mol. Responses to histamine were antagonized by cimetidine but not my mepyramine. Dimaprit also caused vasodilatation. Responses to dimaprit were inhibited by cimetidine 10(-6) to 10(-5) M. A pA2 of 6.43 (6.11 - 6.75, 95% confidence limits) was calculated for cimetidine in the resistance vessels of the hindquarters.
D000818:Animals; D001808:Blood Vessels / Q000187:drug effects*; D002927:Cimetidine / Q000494:pharmacology; D017259:Dimaprit; D006614:Hindlimb / Q000098:blood supply; D006632:Histamine / Q000494:pharmacology*; D006633:Histamine Antagonists / Q000494:pharmacology; D008297:Male; D051381:Rats; D012039:Regional Blood Flow / Q000187:drug effects; D013890:Thiourea / Q000494:pharmacology; D014665:Vasodilator Agents
D006633:Histamine Antagonists; D014665:Vasodilator Agents; D002927:Cimetidine; D006632:Histamine; D013890:Thiourea; D017259:Dimaprit