Pyruvic acid as an intermediary metabolite in the brain tissue of avitaminous and normal pigeons

Abstract

THE recent discovery of a pyruvate reaction in lactate solutions in which avitaminous pigeon's brain has respired in vitro for 2 hours [Peters and Sinclair, 1933] is of interest in relation to the action of vitamin B1, because addition of this reduces the amount of the abnormal substance (for references see Gavrilescu et al. [1932] and Meiklejohn et al. [1932]). More generally, identification of pyruvate in these circumstances lends support from an unexpected source to the recent conceptions of this substance as a normal intermediary in the meta- bolism of carbohydrate in the animal (see especially Embden et al. [1933] and Otherwise these views depend entirely upon work with added sulphite or fluoride. There is also involved the even more fundamental problem of synthesis of carbohydrate from lactic acid, since the indication is that vitamin B, is related to the oxidative synthesis of lactate. With this idea in mind, we have devoted attention in the main to phenomena occurring in lactate solutions, as we are more likely so to approximate to condi- tions favouring the synthesis. The experiments described in this paper have been made with minced brain and in phosphate solutions to facilitate manipulations and to obtain better duplicate control. The conditions are frankly artificial and narrowed for the study of the one point, but it is most unlikely that qualitative errors have been imposed by our conditions. The presence of the substance reacting like pyruvate is equally induced by sections of avitaminous brain and was found by Sinclair (personal communication) to occur with bicarbonate solutions.