RENAL REGULATION OF WATER AND SOME ELECTROLYTES IN MAN, WITH SPECIAL REFERENCE TO THEIR RELATIVE RETENTION AND EXCRETION

Abstract

The renal responses of man to steady intakes of water with or without dissolved electrolytes (NaCl, KHCO3, NaHCO3, KC1, and NH4C1) have been studied. NaCl solns. were administered intraven. and all others orally, at 7 cc./min. for 7 hrs. The minimal isorrheic concn. for Na and Cl of NaCl and for K of KC1 was ca. 15 m.eq./l. The limiting isorrheic concn. for Na, Cl, and K, respectively, was ca. 290, 340, and 70 m. eq./l. Urinary alkaline tides were obtained with all infusions except those of NaCl. Hypertonic solns. of NaCl increase the excretion of K more than hypotonic solns. of NaCl. Curves relating the excretion of NH3 and HC03 to urinary pH were detd. It is believed that the excretion of ammonia in normal man does not play a primary role in the renal regulation of systemic acid-base balance. Ammonia excretion was more highly correlated with urinary pH, however effected, than with any other single variable tested. Classification of diuretics as "osmotic" or "acidifying" is believed inadequate for modern renal physiology. The term "isorrheic diuretic" is suggested for those substances whose diuretic effect is referable to the inability of the kidney to exceed a limiting isorrheic concn. Diuretics are classified as ecuretic when they bring about an absolute dehydration of the body and non-ecuretic when they do not.