Hormonal control of the maintenance of spermatogenesis and sexual segment in the Indian house lizard Hemidactylus flaviviridis Ruppell

Abstract

In the wall lizard Hemidactylus flaviviridis, hypophysectomy results in a marked regression of the testis leading to the elimination of all cell types except the spermatogonia 30 days after pituitary ablation; the sexual segment is also regressed maximally to a condition similar to that seen during the period of sexual quiescence. FSH, LH, or testosterone, either alone or in combinations, were administered for 20 days beginning immediately after hypophysectomy to study the hormonal requirements for the maintenance of the activity of the testis and sexual segment. FSH (10 μg/day) maintained the testis as well as the sexual segment in a condition comparable to that in intact controls. LH (10 μg/day) or testosterone (25 μg/alternate day) maintained the secretory activity of the sexual segment, while in both cases, the testis regressed with extensive desquamation of the cellular elements. Combinations of LH or testosterone with FSH maintained the testis and sexual segment in a condition similar to that seen with FSH alone. These results indicate that FSH may be the only gonadotropic hormone involved in the maintenance of testicular function in the lizard. Since FSH by itself can maintain the androgen-dependent sexual segment, it is possible that FSH also stimulates androgen production in the testis of Hemidactylus.