Lactate dehydrogenase and malate dehydrogenase of Sertoli cells in rats

Lactate-dehydrogenase (LDH) and malate-dehydrogenase (MDH) activities and isozyme patterns of maturing Sertoli cells were investigated in cultured cells obtained from 2-5-week-old rats. Both enzymes, and more strikingly LDH, increased between 2 and 3 weeks of age. LDH isozyme complement included all five isozymes and, in the more mature rats, had a shift toward the isoforms rich in subunit. These data are consistent with an increasing production of lactate/pyruvate and with a finer regulation of this production occurring during the maturing of Sertoli cells. Since lactate/pyruvate are important energy substrates for germ cells, the changes of LDH activity and isozyme patterns of maturing Sertoli cells support their nutritional role in the seminiferous epithelium.