Pharmacological characterization of alpha-adrenergic receptor subtypes mediating contraction in human mesenteric arteries and veins.
Approximately 200 isolated human mesenteric arteries (diameter less than 1 mm) and veins (diameter less than 2 mm) were tested in vitro for their contractile and dilator responses to adrenergic agonists under standardized conditions. This allowed for quantitative estimation of various receptor characteristics: relative agonist potency; concentration for half maximum response (EC50); amount of maximum response (EAm), and affinity of antagonist to receptor (KB and pA2). The contractile response of the vessels to the various sympathomimetic amines involved alpha-adrenoceptors. Postjunctionally, the alpha 1 type of receptor predominated in the arteries whereas the alpha 2-receptor subtype was mainly found in the veins. None of the amines produced any vasodilatory effects in the vessels tested after previous contraction with prostaglandin F2 alpha.
Törnebrandt
K
K
Nobin
A
A
Owman
C
C
D000316:Adrenergic alpha-Agonists / Q000145:classification / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D003000:Clonidine / Q000494:pharmacology; D004347:Drug Interactions; D005260:Female; D006801:Humans; D008297:Male; D008638:Mesenteric Arteries; D008642:Mesenteric Veins; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D010109:Oxymetazoline / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D015016:Yohimbine / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D015016:Yohimbine; D010109:Oxymetazoline; D003000:Clonidine; D009638:Norepinephrine; D011224:Prazosin; D010646:Phentolamine