Origin of lactate dehydrogenase in amniotic fluid.

The origin of protein including enzymes in amniotic fluid is of clinical and research interest. 8 patients were evaluated, with their informed consent, prior to therapeutic abortion. Amniotic fluid, placentas and blood were obtained and lactate dehydrogenase (LDH) isozyme patterns of cell-free amniotic fluid was compared to the LDH patterns of uncultured amniotic fluid cells, maternal serum and RBC, placentas and placental membranes. The LDH isozyme pattern of amnion closely corresponded to that of cell-free amniotic fluid and represents the major source of this enzyme in amniotic fluid.