Pituitary and Serum FSH and LH Levels after Massive and Selective Depletion of the Germinal Epithelium in the Rat Testis*

Abstract

The effects of single and double injections of Busulfan on pituitary and serum LH and FSH were studied in male rats. Two injections of Busulfan produced extensive tubular damage without evidence of concomitant Leydig cell failure. This treatment distinctly elevated LH and FSH in the pituitary and serum. A single injection of Busulfan suspended new spermatogenesis for 5 weeks so that, at various times, the tubules were selectively depleted of spermatogonia, spermatocytes or young spermatids. The depletion of young spermatids correlated with slight but significant elevations of serum LH and FSH. These findings suggest that immature spermatids and in a lesser degree perhaps also primary spermatocytes, may be involved in the feedback regulation of LH and FSH secretion. (Endocrinology92: 48, 1973)