Respiratory Quotient of Cerebral Cortex in B 1 Avitaminosis

Abstract

The investigation of Peters and his coworkers 1 has shown that the ability of the brain to oxidize lactic acid is decreased in polyneuritic pigeons. Since the respiratory quotient of the cerebral cortex of normal animals is unity, 2 probably due to the oxidation of lactic acid, 3 the determination of the respiratory quotient of the cortex during B₁ avitaminosis is of importance.

Three pigeons and one dog were fed on diets deficient in vitamin B₁ and were studied after they showed definite signs of polyneuritis. The respiratory metabolism of the cerebral cortex of the pigeons was examined in the Warburg apparatus. The respiratory quotient of the brain of the dog was determined in 2 ways: (1) directly from the arterial-venous difference of CO₂ and O₂, and (2) the brain was then excised and studied in the Warburg apparatus. The results presented in Table I indicate respiratory quotients below unity probably caused by a diminished ability of the brain to oxidize lactic acid.