NEUROHUMORAL REGULATION OF POTASSIUM BALANCE IN THE DOG

Abstract

The influence of sympatholysis on the distribution of injd. K was studied in 13 dogs anesthetized with Nembutal and made anuric by ligation of the ureters. In one group of animals ergotamine was given and the toxicity of injd. K determined electrocardiographically and correlated with serum concns. The electrocardiographic sequence and the concns. of K at which each event occurred were the same as in the normal animal. In a 2d group of dogs K was first given in amts. adequate to evoke advanced signs of K toxicity, and ergotamine was administered. There was no alteration in the electrocardiographic status to indicate either advance or regression in the degree of intoxication or change in the volume of distribution. In a 3d group ergotamine was given initially and K was injected slowly to achieve high serum concns. as in Group II. Volumes of distributions of K in Groups I and HI, as compared to those in Group II before admn. of ergotamine, were low. Since ergotamine did not produce the electrocardiographic signs of increased K concn. when given to normal dogs or those with increased serum K levels, and did not alter the concns. at which characteristic signs of K toxicity appeared, it was considered possible that the diminution in the apparent volume of distribution of K is a reflection of the reduction in peripheral circulation and does not represent an end result of sympatholysis on K balance in the body.