Walter Hollander

Massive polyuria and natruresis following relief of urinary tract obstruction

Abstract A case report is presented which illustrates the massive urinary loss of sodium, chloride and water which occasionally develops after relief of urinary tract obstruction. Astonishingly high rates of solute and water excretion occurred in this particular patient, apparently, at least partly, the result of an unexpectedly high (normal) glomerular filtration rate and almost certainly augmented unnecessarily by the intravenous administration of glucose-containing fluids with consequent glycosuria. The data collected support the conclusion of Bricker et al. [7] that the proximal portion of the nephrons is the principal site of defective sodium reabsorption. During at least one phase of the diuresis, 24 to 36 hours after its onset, renal excretion of sodium and chloride decreased during an intravenous infusion of 9-alpha-fluorohydrocortisone; however, it is not certain that this was a cause and effect relationship. During the same period evidence was obtained which is interpreted as indicating that the renal tubules were responsive to vasopressin but that the usual renal medullary hypertonicity had been eliminated by the massive solute flow through the loops of Henle.

A STUDY OF THE OSMOTIC BEHAVIOR OF THE HUMAN ERYTHROCYTE

Despite many previous studies of the osmotic properties of erythrocytes, unequivocal answers have not been given to two important questions: 1) Is the erythrocyte in osmotic equilibrium with its normal surrounding fluid? 2) When the osmotic properties of the surrounding fluid are varied, does the erythrocyte gain or lose water to the extent necessary to remain in osmotic equilibrium with the new surroundings-that is, does the erythrocyte behave as a perfect osmometer over a wide range? Previous work related to these questions has been of two general types: measurements of changes of volume of the erythrocytes as the osmotic concentration of the extracellular phase was altered; and measurements of one or more of the colligative properties of the solutions involved. The present study is of the latter type. The osmotic behavior of the normal human erythrocyte has been investigated over a wide range of concentrations by a cryoscopic method and a method for measuring the melting point of microscopic samples. The results give affirmative answers to both of the above questions and illustrate some of the difficulties which may be expected in studies of osmotic properties of any tissues.