[Change in the activity of NAD- and NADP-specific malate dehyrdogenases in oxygen deficiency in different tissues]

NAD-dependent malate dehydrogenase (1.1.1.37) activity was markedly decreased under hypoxia in rat brain and liver mitochondria and cytoplasm; most significant decrease was observed in brain cortex mitochondria. NADP-dependent malate dehydrogenase (1.1.1.40) activity was also reduced under these conditions and the most considerable changes were found in liver mitochondria and cytoplasm. Distribution of activities of these enzymes between subcellular fractions of brain and liver did not change under hypoxia. The oxaloacetate level rised by 20% in brain and decreased by 20-25% in liver under hypoxia.