Studies in avian carbohydrate metabolism

Abstract

The action of vit. B1 "catatorulin effect" upon the brain in vitro of avitaminous pigeons is max. at pH 7.3. It is abolished by cyanide and fluoride in sufficient conc. Na pyrophosphate interacts with vit. B1 and lactate to produce large rises in respiration over periods of 2-3 hrs. Hexosediphosphate and hexosemonophosphate increase the initial rate of respiration in avitaminous as in normal brains, but have no influence in sustaining respiration and show no specific vitamin interaction. [alpha]-Glycero-phosphate increases the respiration, an effect not specifically related to the vitamin action. With lactate alone at pH 6.6 there is no catatorulin effect unless pyrophosphate is added. To some extent [alpha]-glycerophosphate will replace pyrophosphate. It is inferred from this that free pyrophosphate is split off in survival respiration at pH 7.3. Since vit. B1, lactate and pyrophosphate appear to form some coupled oxidation system, the vitamin must influence more than one phase of the energy metabolism of the cell. The facts at present known are the expression of some deep-seated shift in cell equilibria.