Developmental Change and Regional Difference of the Lactate Dehydrogenase Isozyme Pattern in Rat Brain

Postnatal developmental changes of lactate dehydrogenase (LDH : EC 1.1.1.27), malate dehydrogenase and asparate transferase in the nervous tissue of rats have been reviewed by Bonavita (1), and normal topochemical distribution of LDH isozyme in human adult brain was investigated by Gerhardt et al. (12). In recent years, the LDH isozyme in peri-implantation embryos of various animals was studied by several workers (2, 3, 9, 10). But, the continuous developmental changes of LDH from embryonic or fetal brains to postnatal adult ones have not been investigated very much. This approach should be valid for LDH, of which the patterns of relative concentration of isozymes are specific for each tissue at each stage of development (16). Isozymes, which are a refined expression of the enzymatic differentiation of cells, may give some insight into the basic mechanism of cellular differentiation (17). Their analysis contributes to the knowledge of catalytic mechanisms underlying metabolic regulation in the cells. LDH has been one of the most extensively investigated enzymes in this respect. It is the purpose of this study to evaluate the developmental change and regional differences in the LDH isozyme pattern of rat brain.