Mechanisms of fluid and electrolyte retention in experimental preparations in dogs. II. With thoracic inferior vena cava constriction.

Cardiovascular and renal hemodynamic function, nitrogen, electrolyte, and water balances, and circulating eosinophils have been studied before and during the formation of aseites produced by thoracic inferior caval constriction. The data show a striking decrease in the renal and fecal excretion of sodium (Na) and an elevation in fecal potassium (K) output. An analysis of possible factors which might effect the reduction in renal Na excretion demonstrates that neither a low cardiac output nor a depressed glomerular filtration rate is the primary factor.