Renal Na+-K+-ATPase in renin release.
The effects of ouabain and furosemide on renin secretion, renal function, and renal Na+-K+-ATPase were investigated in anesthetized dogs. Furosemide (2 mg/kg) induced significant diuresis, natriuresis, an increase in renal blood flow (RBF), and a fivefold increase in renin secretory rate (RSR), but no changes in glomerular filtration rate (GFR). Infusion of ouabain (1 microgram . kg-1 . min-1) into one renal artery during furosemide diuresis increased fractional sodium excretion from 22 +/- 2 to 30 +/- 3% from the ipsilateral kidney but did not change urine flow, RBF, or GFR, whereas RSR fell to control values (698 +/- 203 to 137 +/- 43). When ouabain preceded furosemide, the rise in RBF and RSR induced by furosemide was abolished but sodium excretion increased. Ouabain infused in vivo inhibited Na+-K+-ATPase in microsomal fractions from cortex (34%) and medulla (27%) as compared with control. Neither saline nor furosemide exerted any effect on Na+-K+-ATPase. Moreover, the effect of ouabain alone on Na+-K+-ATPase was not different from that of ouabain plus furosemide. No changes in Mg2+-ATPase were detected in any of the experiments. These results indicate that inhibition of renal Na+-K+-ATPase abolishes furosemide-induced renin secretion despite potentiation of the natriuretic effect of the diuretic. It is apparent that the level of activity of Na+-K+-ATPase is of prime importance for renin secretion. In addition, ouabain may act directly on the juxtaglomerular cells to inhibit renin secretion.
D000818:Animals; D004231:Diuresis / Q000187:drug effects; D004285:Dogs; D005260:Female; D005665:Furosemide / Q000494:pharmacology; D007668:Kidney / Q000201:enzymology* / Q000502:physiology; D008297:Male; D010042:Ouabain / Q000494:pharmacology; D012083:Renin / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D010042:Ouabain; D005665:Furosemide; D012083:Renin; D000254:Sodium-Potassium-Exchanging ATPase