title: Gonadotropic hormone-releasing hormone (GnRH) bioactivity in the brain of the immature rainbow trout, Salmo gairdneri: the effect of testosterone.
abstract: The effect of exogenous testosterone on the synthesis and release of a bioactive gonadotropic hormone-releasing hormone (GnRH)-like substance has been studied in juvenile male rainbow trout. Long-term testosterone treatment caused an increased gonadotropic hormone (GTH) release and precocious sexual maturity. Tel- and diencephalon extracts from long-term testosterone-treated juvenile rainbow trout showed significantly higher GTH-releasing activity than extracts from control animals when injected in short-term testosterone-pretreated juvenile rainbow trout. It was concluded that long-term testosterone treatment caused an increased synthesis and release of GnRH-like material.
mesh_terms: D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D004027:Diencephalon / Q000502:physiology; D004343:Drug Implants; D008297:Male; D009132:Muscles / Q000502:physiology; D010906:Pituitary Hormone-Releasing Hormones / Q000502:physiology*; D012487:Salmonidae / Q000502:physiology*; D013687:Telencephalon / Q000502:physiology; D013739:Testosterone / Q000008:administration & dosage / Q000494:pharmacology*; D014020:Tissue Extracts / Q000494:pharmacology; D014337:Trout / Q000502:physiology*
chemical_list: D004343:Drug Implants; D010906:Pituitary Hormone-Releasing Hormones; D014020:Tissue Extracts; D013739:Testosterone