Effects of alpha-2-adrenoceptor agonists on induced diuresis in rats.
The alpha-2 adrenoceptor agonists, clonidine, guanabenz, and guanfacine, injected subcutaneously produced a dose-related diuresis. The maximal effect occurred at 2h after administration of clonidine 192 micrograms/kg or 960 micrograms/kg of guanabenz and guanfacine. The alpha-2 antagonist, yohimbine, in doses of 1-8 mg/kg administered prior to the agonists caused a dose-dependent decrease in urine output. The action of the three agonists at alpha-2 adrenoceptors was supported by the observation that the alpha-1 adrenoceptor agonist, prazosin (0.61-2.5 mg/kg), administered prior to each agonist caused an inconsistent decrease in the elevated urinary output caused by clonidine, guanabenz and guanfacine. These results indicate that stimulation of alpha-2 adrenoceptors causes diuresis in the rat.
Shockley
D C
DC
Department of Pharmacology, Meharry Medical College, Nashville, TN 37208.
Wade
L H
LH
Williams-Johnson
M M
MM
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D004231:Diuresis / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006143:Guanabenz / Q000494:pharmacology; D016316:Guanfacine / Q000494:pharmacology; D008297:Male; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000316:Adrenergic alpha-Agonists; D016316:Guanfacine; D006143:Guanabenz; D003000:Clonidine; D011224:Prazosin