THE EFFECT OF POTASSIUM (AND CALCIUM) ON THE CONTRACTIONS OF MAMMALIAN SKELETAL MUSCLE

Abstract

Introduction of a small quantity of a soln. containing 0.2-0.8% KCl into the arterial blood supply of contracting skeletal muscles in cats resulted in a marked temporary increase in height of the contractions, not due to any alteration in the blood supply, whether the muscle was rhythmically stimulated indirectly or directly after curarization, indicating that the effect was on the muscle fibers directly. A similar excess of Ca produced a temporary diminution in the contraction height; solns. with lower concns. of Ca were without effect. These results are contrary to the generally accepted view based on frog muscle experiments.