[Effect of different levels of carbonic acid on activity of dehydrogenases]

A dependence is established for the activity of NADP-dependent isocytrate dehydrogenase and malate dehydrogenase as well as of NAD-malate dehydrogenase on the carbonic acid level. When the biocarbonate concentration in rabbit blood and tissues rise, the activity of cytoplasmic NADP-isocytrate dehydrogenase and NADP-malate dehydrogenase of the liver lowers. The analogous regularity is observed in the in vitro experiments when the bicarbonate concentrations in the medium rises up to 40 mM (within the physiological limits). The activity of NAD-malate dehydrogenase in the soluble fraction of the rabbit liver and kidney increases with the bicarbonate level within the same limits. The found dependence was confirmed in experiments with the enzyme crystalline preparations.