Die renale Elektrolytausscheidung normaler und adrenalektomierter Ratten nach intraven�sen Salzinjektionen und ihre Beeinflussung durch Corticosteroide

Abstract

Groups of normal rats of both sexes in moderate water diuresis received i.v. injections of 5 ml./kg, of hypertonic (5 times isoosmotic) solutions of sodium chloride, mannitol er sodium sulfate. The renal excretion of water, sodium, chloride and potassium in a 30 minute-period following this injection was measured. It was compared to control values obtained 40 minutes earlier in the same animals after an i.v. injection of isotonic glucose solution. All hypertonic solutions increased diuresis, natriuresis, chloruresis and kaliuresis. While the effects of mannitol and sodium chloride were comparable, sodium sulfate was more natriuretic and less chloruretic. The excretion of potassium after injection of sodium sulfate was twice as high than after injection of sodium chloride or mannitol. The kaliuretic effeet of sodium chtoride in rats, therefore, is assumed to be due to an increase in the excretion of sodium rather than of chloride. Under the same conditions the renal exeretion of water, Nu+, K+ and Cl' after i.v. injections of either isotonic glucose solution or 4.5 per cent NaCl solution (5 ml/kg.) was studied in large groups of adrenalectomized or sham-operated rats, untreated or treated with Cortisone, Cortexone, Aldosterone or Corticotropin. The influences of adrenalectomy and of the various hormones are described in detail. They were quite similar to the effects observed in isotonic saline diuresis after oral administration of large volumes of 0.9 per cent NaCl solution. I t was concluded that the changes observed in isotonic saline diuresis after adrenalectomy or in corticosteroid-treated rats are not due to changes in intestinal absorption, but rather to primary changes in renal excretion. Furthermore, the “kaliuretic” effect of an increase in urinary sodium excretion was found not to be abolished by adrenalectomy, as opposed to hypophyseetomy.