Oxidation of Extramitochondrial Diphosphopyridine Nucleotide by Various Tissues of the Mouse

Exogenous reduced diphosphopyridine nucleotide was not oxidized by mitochondria but by cytoplasmic hydrogen-accepting systems catalyzed by lactic, α-glycerophosphate, and malic dehydrogenases. The three enzymes were found in all tissues of the mouse; the amount of activity of each enzyme differed in the various tissues, however. It is suggested that each tissue has a unique pattern for oxidation of extramitochondrial diphosphopyridine nucleotide.