title: Effects of alpha-agonist on renin and prostaglandin E2 release in anesthetized dogs.
abstract: The relationship between renin release and renal prostaglandin (PG) production induced by the alpha-agonists methoxamine and alpha-methylnorepinephrine was examined in anesthetized dogs. Both intrarenal infusions of methoxamine (1, 3, and 5 micrograms/min) and alpha-methylnorepinephrine (0.37, 1, and 2 micrograms/min) resulted in a dose-dependent decrease in renal blood flow to a slight degree. Methoxamine dose-dependently increased the renin secretion rate but failed to increase the PGE2 secretion rate. In contrast, alpha-methylnorepinephrine failed to affect the renin secretion rate but dose-dependently increased the PGE2 secretion rate. The effect of methoxamine (5 micrograms/min) on renin release was abolished by the intrarenal alpha 1-adrenoceptor blockade with prazosin (3 micrograms/min) but was not affected by the intrarenal alpha 2-adrenoceptor blockade with yohimbine (30 micrograms/min). The effect of alpha-methylnorepinephrine (2 micrograms/min) on PGE2 release was abolished by yohimbine but not by prazosin. These results suggest that there is a dissociation between renin release and renal PG production induced by alpha-agonists and that renal alpha 1- and alpha 2-adrenoceptors may participate in renin and PGE2 release, respectively.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000768:Anesthesia, General; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D015232:Dinoprostone; D004285:Dogs; D005260:Female; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008729:Methoxamine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D008771:Nordefrin / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011458:Prostaglandins E / Q000378:metabolism*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects* / Q000378:metabolism; D012079:Renal Circulation / Q000187:drug effects; D012083:Renin / Q000378:metabolism*; D015016:Yohimbine / Q000494:pharmacology
chemical_list: D000316:Adrenergic alpha-Agonists; D011458:Prostaglandins E; D011942:Receptors, Adrenergic, alpha; D015016:Yohimbine; D012083:Renin; D008729:Methoxamine; D015232:Dinoprostone; D008771:Nordefrin; D011224:Prazosin