On the localization of lactate dehydrogenase in the ovaries and reproductive tracts of rats and mice.

The localization of lactate dehydrogenase in the ovaries and reproductive tracts of rats and mice has been studied by a methodology which minimizes loss of this soluble enzyme by diffusion, and allows comment on the subunit composition of the cellular enzyme. The results differ significantly from previous data with conventional methodologies. In particular, the major localization of activity in the present study was identified in interstitial cells, and not the corpora lutea or granulosa cells; and it was noticeable that neither species exhibited massively greater expression of lactate dehydrogenase activity in the oocytes than in adjacent cell types of the reproductive tract. The goblet cells of the Fallopian tube stained intensively for activity of this enzyme. These results have been discussed in relation to the discordant data in the literature, the important role of lactate dehydrogenase in mammalian development, and the evidence for a masking of the activity of this enzyme in oocytes and pre-implantation ova.