EFFECT OF CYANIDE ON PRIMARY MUSCLE TYPES

¹ Department of Physiology, University of Minnesota Medical School, Minneapolis, Minnesota

Skeletal muscle of the frog after the administration of cyanide showed little change in the curve of contraction other than a slight lengthening of the contraction phase. The contraction curve of the artificially stimulated rectal muscle, however, showed slow relaxation after cyanide, while the latent and contraction periods were shortened. The frog heart was immediately killed by intraventricular injection of cyanide, while the turtle heart was stimulated by the same dose. The perfused rabbit heart was at first stimulated by the cyanide and then ceased to beat and passed into a condition of extreme rigor. Although the heart beat was decreasing, temporary revival could be obtained by the addition of glutathione or epinephrine to the perfusate, but this effect was finally lost.