Pretreatment with GnRH antagonist causes partial restoration of testicular tissue after kisspeptin-10 induced degeneration in prepubertal rats

Hypothalamus-derived kisspeptins are critical regulators of reproduction in nearly all mammalian species. How kisspeptins regulate gonadal maturation in sexually immature male mammals remains elusive. For this purpose, prepubertal rats were assigned to four experimental groups namely: control (saline treated), kisspeptin alone, saline with acyline pretreatment (saline + acyline pretreated) and kisspeptin with acyline pretreatment (kisspeptin + acyline pretreated). Acyline was administered prior to kisspeptin treatment at the rate of 300 mug/kg body weight. Kisspeptin and saline were administered intraperitonealy at 1 mug/rat twice daily to prepubertal male rats. Effects on spermatogenesis, levels of testosterone, LH and FSH, histomorphology and ultrastructure of testicular tissue were studied. At the end of treatments plasma FSH levels were not altered in kisspeptin alone treatment group while it decreased (P less than 0.001) in the saline (acyline pretreated) treated group, and in the kisspeptin (acyline pretreated) treated group. LH (P less than 0.001) and testosterone (P less than 0.01) concentrations were reduced in all treated groups. Alone kisspeptin and saline (acyline pretreated) treatment adversely affected all testicular parameters. In the kisspeptin (acyline pretreated) treatment group, only type A spermatogonia decreased (P less than 0.001) significantly while other parameters remained unaffected. Histomorphology and ultrastructure showed atrophied germinal epithelium with alone kisspeptin and saline (acyline pretreated) treatment, while seminiferous tubules of rats treated with kisspeptin (acyline pretreated) revealed partial restoration of spermatogenesis. The present findings indicate that subchronic kisspeptin administration may act as a suppressor of pubertal maturation during non-pubertal states and a partial recovery of the testicular tissue occur with acyline pretreatment.