Bolism of Normal Tissue Extracts

THE production of lactic acid from hexosediphosphate and hexosemonophosphate by extracts of muscle and tumour tissue, at an optimum temperature of 5055°, has been demonstrated by Scharles et al. [1935]. Using extracts of various transplantable mouse tumours with hexosediphosphate as substrate Mawson [1936] confirmed these results and found that prolonged dialysis of the extracts considerably reduced their glycolytic activity. The activity was restored, however, by addition of glutathione and the suggestion was made that the lactic acid was formed by means of methylglyoxalase. This hypothesis was supported by the observation that the yield of lactic acid was greatly reduced by the addition of extracts of dried kidney, which are known to contain an antiglyoxalase [Woodward et al. 1935]. Since little lactic acid was formed by tumour extracts at 380 even in the presence of glutathione it was concluded that the conversion of hexosediphosphate into methylglyoxal could only take place at higher temperatures, and it was thought unlikely that this part of the reaction was of an enzymic character. The investigation of the conversion of hexosediphosphate into lactic acid by tissue extracts at high temperatures has been carried out chiefly with malignant tissue and it seemed desirable that information should be obtained on the activity of normal tissue extracts under similar conditions. The present paper records an investigation of the hexosediphosphate metabolism at high temperatures of extracts of blood, brain, kidney, liver, muscle, spleen and testis of mice and rats. EXPERIMENTAL