Response of isolated perfused dog kidneys to epinephrine

Abstract

To investigate the renal vascular changes induced by epinephrine, 21 isolated dog kidneys were perfused at constant pressure. Single injections and constant infusions of epinephrine were administered. Changes in blood and urine flow and arterial and intrarenal venous pressures were measured. Changes in renal volume were estimated with a kidney-weighing device, and determinations of cation concentrations were carried out. Data do not support the view that low doses of epinephrine cause diuresis. The previously reported afferent dilation and efferent constriction after epinephrine administration were not found in this investigation. Both increased and decreased urine flows were noted at low doses of epinephrine, whereas a fall in urine flow was consistently seen at high doses. The primary vascular effect of epinephrine is presumably on the afferent arteriole, since there was no consistent diuresis, no increase in kidney weight, a decrease in blood flow, and a decrease in filtration. Electrolyte excretion was not directly influenced by epinephrine. The pressure in the ureter was changed by epinephrine.