Effect of epinephrine infusion on plasma potassium and its urinary excretion in rats subjected to subtotal nephrectomy.

Extrarenal potassium handling plays pivotal role in potassium homeostasis and is regulated by several hormones including epinephrine. The aim of this study was to look how epinephrine affects both extrarenal and renal potassium handling in rats with chronic renal failure. In subtotally nephrectomized rats, epinephrine (0.05 micrograms/kg per h) plus KCl (0.5 mmol/kg per h) were infused i.v. Plasma potassium and its fractional urinary excretion were measured simultaneously in five clearance periods. Each clearance period lasted 20 min and glomerular filtration rate was estimated as inulin clearance. Regardless of epinephrine infusion plasma potassium as well as fractional potassium excretion were higher in rats with chronic renal failure than in controls (shame--operated). It was concluded that the effect of epinephrine on both extrarenal and renal potassium handling was ameliorated in rats with chronic renal failure.