Arginine hydrochloride stimulation of serum potassium and aldosterone is enhanced by somatostatin-28

Abstract

Abstract. Potassium, aldosterone and insulin responses to arginine infusion were compared in 5 normal men during infusions of somatostatin-14 (SS-14), somatostatin-28 (SS-28) and a control infusion. SS-14 and SS-28 were infused continuously at a rate of 8.6 pmol/min/kg and arginine (0.5 g/kg) was infused from 30–60 min. Following the control infusion with arginine hydrochloride, serum aldosterone and potassium levels increased slightly. The rise in potassium appears to be due to an exchange of cellular potassium for the proton from the arginine hydrochloride. SS-14 had no significant effect on serum potassium or aldosterone but an equimolar dose of SS-28 significantly enhanced the rise in potassium and aldosterone. SS-28 completely inhibited the arginine-stimulated insulin increase while SS-14 only partially inhibited the insulin increase. Since insulin opposes the increase in serum potassium by stimulating cellular uptake of this cation, the enhanced rise in serum potassium in response to arginine hydrochloride during the SS-28 infusion is likely due to the potent insulin suppressing effect of SS-28. The rise in serum aldosterone is directly related to the degree of elevation of serum potassium. These findings caution against the infusion of SS-28 during an arginine stimulation test.