Abstract
Reserpine increased the concentration of potassium ions in the fluid bathing the isolated frog sartorius muscle. The effect of reserpine upon respiration and upon glycolysis in rabbit intestinal muscle has been investigated using the Warburg "Direct" method. After a latent period, reserpine (50 mug./ml.) depressed respiration but did not affect glycolysis in gut muscle. These results, together with previous observations, may point to an effect of reserpine upon carbohydrate metabolism.