Estimation of glutathione in purified populations of mouse testis germ cells

Glutathione (GSH), a ubiquitous cysteine-containing tripeptide, is present in high concentration in adult mouse testis (4.3 +/- 0.2 mumol/g). Examination of testis at 0, 7, 14, 21, 28, 35, 42, 50, and 60 days of age reveals that the level of testicular GSH, only 1.4 +/- 0.1 mumol/g in neonates, increases steadily until 28 days of age, when the adult level is reached. An even steeper increase in GSH concentration, when expressed in mumol/mg DNA, is seen between 0 days (0.19 +/- 0.01) and 42 days (1.19 +/- 0.05), at which time the adult level is attained. Enzymatic dissociation of 4-wk-postnatal seminiferous epithelium, using collagenase and dispase either sequentially or in combination, followed by unit gravity sedimentation, yielded maximal GSH concentrations (mumol/mg DNA) in those cell fractions most enriched in pachytene spermatocytes, followed by a second slightly lower peak of activity in the purest round spermatid fraction, which may have lost a significant percentage of its original GSH content. A relatively high GSH content in condensing spermatids, which are at present not isolable without loss of cytoplasm, is implied by the continually increasing levels of testicular GSH/mg DNA between 28 and 42 days of age. It is proposed that retention of GSH is a sensitive indicator of germ cell viability following cell separation procedures. The functions of GSH during meiotic and postmeiotic germ cell development may include protection against mutagens and reduction of disulfide bonds during the processing of cysteine-containing proteins.