Measurement of seminal LDH-X and transferrin in normal and infertile men

LDH‐X, an isoenzyme of lactate dehydrogenase specific for germinal epithelium activity, has been measured in the seminal plasma of infertile subjects whose infertility had different origins. In the same samples, seminal transferrin, an index of Sertoli cell function, was also measured. In this investigation, seminal LDH‐X was not detectable in the vasectomized subjects, in patients with azoospermia due to seminiferous tubular damage, nor in patients who showed a marked decrease in sperm concentration (