A gonadotropin releasing hormone analog induces spermiation in intact and hypophysectomized frogs, Rana esculenta.
The sperm-releasing activity of a gonadotropin releasing hormone (GnRH) agonist, Buserelin (GnRH) and hypophysis homogenate (PD) preparations was studied in intact and hypophysectomized (PDX) frogs, Rana esculenta. In addition, human chorion gonadotropin (hCG) was tested in PDX animals, and GnRH antagonist (GnRHA) treatments were carried out in intact and PDX animals, in combination with the hormonal injections. GnRH or PD treatments were able to elicit spermiation in intact and PDX animals. While GnRH, injected 24 h later, was again effective in inducing spermiation in intact animals, this was not the case in PDX frogs. GnRHA counteracted GnRH effects in intact frogs. Moreover, in PDX animals GnRHA injections counteracted the sperm-releasing activity induced by hCG or GnRH, but failed to inhibit sperm-releasing activity induced by PD homogenate.
Minucci
S
S
Istituto di Biologia, I Facoltà di Medicina e Chirurgia, Napoli, Italy.
Di Matteo
L
L
Chieffi Baccari
G
G
Pierantoni
R
R
D000818:Animals; D002064:Buserelin / Q000494:pharmacology*; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D007016:Hypophysectomy; D008297:Male; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D011893:Rana esculenta; D012671:Seminiferous Tubules / Q000166:cytology* / Q000187:drug effects; D013094:Spermatozoa / Q000502:physiology*; D013737:Testis / Q000166:cytology* / Q000187:drug effects
D006063:Chorionic Gonadotropin; D007987:Gonadotropin-Releasing Hormone; C034511:LHRH, pGlu(1)-Phe(2)-Trp(3,6)-; D002064:Buserelin; D011761:Pyrrolidonecarboxylic Acid