[Ultrastructural localization of lactate dehydrogenase activity in the brain cells of human embryos]

Results of studying the ultrastructural localization of lactate dehydrogenase (LDH) in the brain neuroectodermal cells of 7-11-week-old human embryos are presented. Young neurons and glioblasts display marked LDH activity. The reaction product is more frequently found in young neurons as compared to glioblasts. The number of active glial cells grows with embryonic development. The use of different incubation media makes it possible to differentiate the LDH-associated activity from the activity of succinate dehydrogenase, which oxidizes the endogenous tissue substrate. LDH is localized in mitochondria and hyaloplasm, while the activity in the plasma membranes and lamellar structures (detected by the ferrocyanide method) is largely related to succinate dehydrogenase functioning.