Observations on tissue glycolysis

Abstract

Similar to K+, Rb+ and Cs+, NH4+ (M/30 NH4C1) increased respiration in brain slices; it increased aerobic glycolysis to the anaerobic level and inhibited anaerobic glycolysis. Some increase of aerobic glycolysis was still seen with concs. of M/1000-M/3000 NH4CI. Spleen was the only other tissue showing a similar effect of M/30 NH4C1. M/100-M/1000 l ( + ) glutamic acid inhibited anaerobic glycolysis of brain slices by 30-70%; d([long dash]) glutamic acid, l-glutamine and dl-[beta]-hydroxyglutamic acid acted similarly. The effect was only observed in brain. The effect of glutamic acid was increased by the addition of M/100 lactate or succinate and was largely reversed by M/100-M/1000 pyruvate. On aerobic glycolysis the substances of the glutamic acid group had the opposite effect, increasing Qa 5-8. This effect, too, occurred only in brain. M/50 maleic acid inhibited the respiration of brain slices in bicarbonate-glucose-Ringer to a varying degree from 10 to 50%. Aerobic glycolysis rose slowly and reached the anaerobic level during the 3rd hr. of the expt. No other simple organic acid had a similar effect. M/50 glutamate and M/50 citrate accelerated the effect of maleate; M/50 pyruvate largely abolished it. Reduced glutathione did not reverse the effect of maleic acid, but like glutamic acid enhanced it. The effect of maleic acid was partly reversed by washing. In embryo, heart and spleen, maleic acid increased aerobic glycolysis, sometimes to the level of the anaerobic.