The role of the renin-angiotensin system in mediation of adrenal catecholamine secretion in the cat induced by intrarenal beta-adrenergic stimulation.
Isoproterenol infusion (0.1 microgram/kg per min) into the renal artery of the cat induced an increase in plasma renin concentration (PRC) from 14.3 +/- 5.7 (mean +/- SE) ng angiotensin I/ml per hr to 56.8 +/- 7.7 after 70 minutes (P < 0.05) and an increase in catecholamine secretion rate from 38.7 +/- 6.0 ng/kg per 10 min to 180.0 +/- 40.0 after 70 minutes (P < 0.001). Intravenous infusion of the same dose of isoproterenol had no significant effect on adrenomedullary catecholamine secretion rate. Isoproterenol induced preferential norepinephrine release: the ratio of norepinephrine to epinephrine secretion changed from 11.5:23.7 during the control period to 130.0:40.1 70 minutes after the start of isoproterenol administration. Intrarenal infusion of propranolol (3.0 mg/kg per min) inhibited renal renin release and adrenal catecholamine secretion in response to intrarenal isoproterenol. Intravenous infusion (0.4 microgram/kg per min) of an angiotensin II antagonist [Sar1, Ileu8]angiotensin II abolished the catecholamine response to intrarenal isoproterenol infusion. It is suggested that intrarenal isoproterenol infusion stimulates renal renin release and angiotensin production which, in turn, stimulates a preferential secretion of adrenomedullary norepinephrine.
D015059:1-Sarcosine-8-Isoleucine Angiotensin II / Q000494:pharmacology; D000313:Adrenal Medulla / Q000503:physiopathology; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002395:Catecholamines / Q000378:metabolism; D002415:Cats; D007545:Isoproterenol / Q000008:administration & dosage; D011433:Propranolol / Q000008:administration & dosage; D012083:Renin / Q000097:blood / Q000494:pharmacology*
D002395:Catecholamines; D000804:Angiotensin II; D015059:1-Sarcosine-8-Isoleucine Angiotensin II; D011433:Propranolol; D012083:Renin; D007545:Isoproterenol