Expression of functional postjunctional alpha 2-adrenoceptors in rabbit isolated distal saphenous artery--a permissive role for angiotensin II?
In the rabbit isolated distal saphenous artery, the population of postjunctional adrenoceptors is of the alpha 1 variety under normal in vitro experimental conditions, based on the potency order of selective agonists and on the effects of the antagonists prazosin and rauwolscine against responses to UK-14304. Angiotensin II (A II, 0.05 microM) however, without affecting resting baseline tension, markedly enhanced responses to UK-14304, particularly at low concentrations. This previously unseen component of the response to UK-14304 was resistant to prazosin (0.1 microM) but susceptible to rauwolscine (1 microM). A II would therefore appear to have a permissive role for the expression of a quiescent population of postjunctional alpha 2-adrenoceptors in the rabbit distal saphenous artery.
Dunn
W R
WR
Autonomic Physiology Unit, University of Glasgow.
McGrath
J C
JC
Wilson
V G
VG
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000804:Angiotensin II / Q000502:physiology*; D000818:Animals; D001158:Arteries / Q000187:drug effects; D000068438:Brimonidine Tartrate; D004347:Drug Interactions; D066298:In Vitro Techniques; D008297:Male; D011224:Prazosin / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology*; D011817:Rabbits; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects*; D015016:Yohimbine / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D011810:Quinoxalines; D011942:Receptors, Adrenergic, alpha; D000804:Angiotensin II; D015016:Yohimbine; D000068438:Brimonidine Tartrate; D011224:Prazosin