[Lactate dehydrogenase activity of the ova and early embryos in BALB/c and C57BL/6 mice and their reciprocal hybrids].

The lactate dehydrogenase (LDH) activity in eggs and 8-cell mouse embryos of BALB/c, C57BL/6 strains and their reciprocal hybrids was studied. LDH pattern of mouse eggs and 8-cell embryos is represented by only one fast migrating isozyme LDH-1. For determining the water-soluble LDH activity water extraction of enzyme was used. For determining the total LDH activity triton X-100 extraction of enzyme was used. The bound LDH activity was estimated as a difference between total LDH and water-soluble LDH activities. The total LDH activity of eggs and 8-cell embryos for all genotypes is reliably higher than the water-soluble LDH activity. Differences between strains and hybrids are reliable. There is diversity of values of eggs and 8-cell embryos LDH activity. The diversity of values of water-soluble LDH activity is higher than that of the total LDH activity in all cases. The development from the egg to 8-cell embryo is accompanied by the decrease of the total LDH activity, the water-soluble LDH activity and the bound LDH activity for all genotypes except BALB/c. Only the water-soluble LDH activity decreases by BALB/c strain.