Role of Insulin in the Transfer of Infused Potassium to Tissue

Abstract

Dogs with ligated ureters were infused with KCl at rates that varied from 0.2 to 3 mEq/kg/hr, and infusion continued until the onset of cardiac manifestations of hyperkalemia, when serum potassium ranged between 9.9 and 11.0 mEq/L. It was found that ligated dogs were able to remove much of the infused potassium from extracellular fluid despite the suppression of urinary excretion. Pancreatectornized dogs lost the ability to remove infused potassium from extracellular fluid; treatment with insulin restored it completely. Addition of insulin (5U/kg/hr) to the infused KCl markedly augmented both the rate of potassium removal from extracellular fluid and the amount sequestered outside the extracellular compartment. In non-pancreatectomized ligated dogs, the maximal rate of potassium removal without exogenous insulin was ∼ 0.5 mEq/kg/hr, and maximal potassium sequestered 3.3 mEq/kg. Insulin added to the KCl infusion increased the rate to ∼ 1.6 mEq/kg/hr and the amount sequestered to ∼ 6.2 mEq/kg. Insulin may have an important physiological role in the regulation of serum potassium.