Lactic and malic dehydrogenases in human fetal tissues.

The nonparticulate fraction of homogenates of heart, liver, kidney, lung, and cerebral cortex from human fetuses of varying gestational ages was subjected to electrophoresis on starch grains. Five lactic dehydrogenases and two malic dehydrogenases with characteristic rates with pyridine nucleotide analogs were found in all tissues at all ages. Quantitative differences in the relative proportions of these peaks were observed as gestation proceeded.