Renal function and Na-K-ATPase in rats after suprarenal ligation of inferior vena cava.
To assess the effects of altered renal function on Na-K-ATPase, the following groups of rats were studied: 1. rats with suprarenal vena cava ligation (SVCL), la. DOCA-treated rats with SVCL, 2. rats with infrarenal vena cava ligation (IVCL), 3. rats with glycerol-induced acute renal failure, 4. rats with bilateral ureteric ligation, and 5. K-exalate-treated rats with SVCL. In group 1, acute renal failure with hyperkalemia developed and medullary Na-K-ATPase increased from 95 +/- 5 in control to 155 +/- 7 mumol Pi/mg prot/h, P less than 0.001, DOCA did not prevent the increase of Na-K-ATPase. In group 2, medullary Na-K-ATPase decreased from 130 +/- 10 in control to 88 +/- 7, P less than 0.01, in rats with IVCL. In group 3, cortical Na-K-ATPase decreased from 55 +/- 5 to 27 +/- 6, P less than 0.02. In group 4, Na-K-ATPase was unchanged. In group 5, maintenance of normokalemia prevented the rise in Na-K-ATPase. These experiments demonstrated a K-dependent activation of medullary Na-K-ATPase after SVCL but not in other forms of renal failure. Because SVCL diminishes drastically GFR per nephron, the present findings imply that increased loads of Na and K per nephron are not a prerequisite for an increase in medullary Na-K-ATPase. Hyperkalemia in presence of increased renal venous pressure seems to be causally related to the rise in medullary Na-K-ATPase activity.
D000251:Adenosine Triphosphatases / Q000032:analysis; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D002302:Cardiac Output; D003900:Desoxycorticosterone / Q000494:pharmacology; D005990:Glycerol; D007668:Kidney / Q000201:enzymology / Q000503:physiopathology*; D007674:Kidney Diseases / Q000201:enzymology / Q000503:physiopathology*; D007683:Kidney Tubular Necrosis, Acute / Q000201:enzymology; D008026:Ligation; D008297:Male; D009392:Nephrectomy; D011188:Potassium / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis*; D014513:Ureter / Q000601:surgery; D014682:Vena Cava, Inferior / Q000601:surgery
D003900:Desoxycorticosterone; D012964:Sodium; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D005990:Glycerol; D011188:Potassium