[Characterization of the alpha adrenoreceptors in the vascular bed of the isolated rat kidney].
The vasoconstrictive effect of alpha-adrenoceptor agonists was studied on isolated perfused kidney from normal Wistar rats. Methoxamine (ED50 = 1.61 +/- 0.16 X 10(-6) M; m +/- SEM), phenylephrine (2.33 +/- 0.16 X 10(-6) M) and alpha-methylnoradrenaline (1.60 +/- 0.40 X 10(-6) M) acted as full agonists. Dopamine (9.5 +/- 1.08 X 10(-5) M) had a partial agonistic effect. Clonidine and B-HT 920 were inactive up to the concentration of 10(-4) M. Prazosin, but not yohimbine (10(-6) M) antagonized the response to phenylephrine (pA2 = 8.48 +/- 0.12) and to alpha-methylnoradrenaline (8.02 +/- 0.10). Our results suggest that the postsynaptic alpha-adrenoceptors which when stimulated increases vascular resistance of isolated rat kidney, belong exclusively to the alpha 1-subtype.
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D066298:In Vitro Techniques; D007668:Kidney / Q000098:blood supply* / Q000294:innervation; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects; D014666:Vasomotor System / Q000187:drug effects*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D011942:Receptors, Adrenergic, alpha
Caractérisation des alpha-adrénorécepteurs du lit vasculaire du rein de rat isolé.