Patterns of lactate dehydrogenase isoenzymes during gonadogenesis in the rat

The isoenzymes of LDH were detected by polyacrylamide gel electrophoresis. The M and H LDH subunits were present in gonads of both sexes from Day 14 1/2 p.c. and there was some variation with increased gestation. From Day 20 after birth two specific LDH-X bands (X1 and X2) were evident in the spermatocyte-rich fraction, but not in those of the Sertoli and Leydig cell fractions or those of the ovary.