Growth Hormone Advances Spermatogenesis in Premature Rats Treated with Gonadotropin-Releasing Hormone Agonist.

Abstract

Abstract.To clarify the effect of GH on the development of seminiferous tubules in premature male rats, we investigated whether GH accelerates spermatogenesis under the condition of gonadotropin deprivation.Male Wistar rats aged three weeks were divided into three groups and subjected to administration of either long-acting GnRH agonist (GnRHa) or a combination of GnRHa and rat GH, with normal saline solution as control. After the 4-week treatment, sperm density and motility in the right epididymis were measured and seminiferous tubules of right testes were histologically examined. Sperm density and motility were significantly higher in GnRHa+GH-treated rats than in GnRHa-treated rats. In histological examination, the numbers of germ cells in various stages were increased in GnRHa+GH-treated rats compared with GnRHa-treated rats, with the number of mature spermatid being noticeably higher in GnRHa+GH-treated rats. These results suggest that administration of GH decreases loss of germ cells at various stages of spermatogenesis under the condition of gonadotropin withdrawal.

Growth Hormone and Reproduction: A Review of Endocrine and Autocrine/Paracrine Interactions

“…The impact of GH on testicular growth may reflect germ cell proliferation, particularly in situations that impair spermatogenesis. GH partially compensates for GnRH immunoneutralization by increasing the number of mature spermatids in prepubertal male rats [ 83 ]. In GH-deficient dwarf rats, GH prevents the decrease in spermatid count and spermatozoa motility resulting from treatment with cyclophosphamide, a chemotherapeutic drug with strong testicular toxicity [ 84 ].…”

Daily Testosterone and Gonadotropin Levels Are Similar in Azoospermic and Nonazoospermic Normal Men Administered Weekly Testosterone: Implications for Male Contraceptive Development

“…Alternatively, growth hormone (GH) has recently been shown to support spermatogenesis in rats chemically hypophysectomized with gonadotropin-releasing hormone agonists (Ohyama et al, 1999). If GH acts as a ''cogonadotropin,'' it may be possible that differences in the GH/ insulin-like growth factor-1 axis could discriminate between men who suppress to azoospermia and those who do not.…”

Growth hormone and growth hormone gene of the American mink (Neovison vison) – the current state of knowledge of one of the key hormones in one of the most intensively economically exploited species

“…In males, GH conditions the proper growth and development of testes (Ohyama et al, 1999;Hull, Harvey, 2000b). Somatotropin takes part in the differentiation of Leydig cells (Kulin et al, 1981;Kanzaki, Morris, 1999).…”