ON THE SOURCE OF ENERGY FOR ANAEROBIC CONTRACTION IN GLYCOGEN-POOR MUSCLE

Abstract

Experiments on 48 grass and bull frogs, using the procedure of Olmsted and Coulthard, and 15 large bull frogs, with a modification of the procedure to allow the measurement of developed tension as well as glycogen and lactic acid, showed that within the limits of experimental error the lactate accumulation in anaerobic contraction to fatigue is entirely balanced by the loss in glycogen in glycogen-poor, as well as in glycogen-rich muscle. In 24 experiments recording isotonic contractions the authors have found that the magnitude of the mechanical response is invariably proportional to the quantity of lactate formed from glycogen. From these studies there is no evidence that the energy for tension development in muscle poor in glycogen arises from a different source than in muscles rich in glycogen.