title: Ouabain inhibits renin release by a direct renal haemodynamic effect.
abstract: The effect of intrarenal infusion of ouabain (90 micrograms/kg) on renin release was examined in the anaesthetized dog. Ouabain reduced cortical Na-K-ATPase activity to 23% and outer medullary activity to 18% of the control level. During renal arterial constriction to a perfusion pressure below the autoregulatory range, renin release rose from 1.2 +/- 0.4 to 47.4 +/- 6.9 micrograms/min (P less than 0.001). This response was abolished by ouabain. When superimposed on renal arterial constriction, beta-adrenergic stimulation enhanced renin release from 25.6 +/- 10.7 to 56.9 +/- 9.5 micrograms/min (P = 0.02) at a urinary sodium excretion of 2 +/- 1 mumol/min. After ouabain, the corresponding increment substantially decreased since release rose from 5.6 +/- 2.0 to 19.9 +/- 5.3 micrograms/min only (P = 0.02), at a urinary sodium excretion of 140 +/- 67 mumol/min. When glomerular filtration was reduced to zero by ureteral occlusion in one series, renin release increased to 22.6 +/- 5.1 but was reduced (P less than 0.05) by ouabain to 13.5 +/- 5.5 micrograms/min and superimposed isoproterenol had no effect. According to these observations, ouabain inhibits renin release by a direct effect on the afferent arteriole through constriction of the autoregulating renin-secreting segment.
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D004285:Dogs; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006706:Homeostasis / Q000187:drug effects; D007269:Injections, Intra-Arterial; D007545:Isoproterenol / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects*; D007928:Lethal Dose 50; D008297:Male; D010042:Ouabain / Q000008:administration & dosage / Q000494:pharmacology*; D012077:Renal Artery / Q000502:physiology; D012079:Renal Circulation / Q000187:drug effects; D012083:Renin / Q000378:metabolism*; D012964:Sodium / Q000652:urine; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014517:Ureteral Obstruction / Q000503:physiopathology
chemical_list: D000318:Adrenergic beta-Agonists; D010042:Ouabain; D012964:Sodium; D012083:Renin; D000254:Sodium-Potassium-Exchanging ATPase; D007545:Isoproterenol