Cliii. Carbohydrate Metabolism in Birds. Iii. the Effects of Rest and Exercise upon the Lactic Acid Content of the Organs of Normal and Rice-fed Pigeons

KINNERSLEY AND PETERS [1929, 1930] have demonstrated that there is an increase in the lactic acid content of the brain of the pigeon in polyneuritis (induced by feeding on polished rice) and that the increase is particularly marked in the midand hind-brain. They were inclined to interpret their results as an indication that a local defect in the metabolism of this lower part of the brain was responsible for the symptoms of polyneuritis, but it seemed to be of interest to investigate the lactic acid contents of other organs of the body in order to determine whether the phenomenon they observed was in fact a part of a more general disturbance. With this end in view a technique was developed for the use of iodoacetic acid as a "fixative" for lactic acid in the organs of the pigeon, in the hope that it might prove possible to obtain satisfactory estimates of the lactic acid contents of the pectoral muscle, the heart and the liver of the same bird. A preliminary account of this technique has already been published [Fisher, 1931]. In the course of an attempt to obtain standard conditions in the birds used for estimations it was discovered accidentally that the lactic acid contents of organs of polyneuritic pigeons depended to a considerable extent on the conditions of the experiment. This finding has been expanded, and in consequence the results, as presented, are not strictly complementary to those of Kinnersley and Peters. But they serve the original purpose in that they demonstrate that there is a definite general defect in lactic acid metabolism in the polyneuritic pigeon, in addition to the local defect described by Kinnersley and Peters. METHODS. Lactic acid fixation. The use of iodoacetic acid as a fixative is based on Lundsgaard's [1930] original observation that lactic acid is apparently not formed in the stimulated gastrocnemius of a frog previously poisoned with the drug. The applicability of his assumption to normal pigeon muscle was