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 spermreleasing activity induced by hCG or GnRH*, but failed to inhibit sperm-releasing activity induced by PD homogenate. © 1989 Birkhäuser Verlag.
A gonadotropin releasing hormone analog induces spermiation in intact and hypophysectomized frogs, Rana esculenta
MINUCCI, Sergio;DI MATTEO, Loredana;CHIEFFI, Gabriella;PIERANTONI, Riccardo
1989
Abstract
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 spermreleasing activity induced by hCG or GnRH*, but failed to inhibit sperm-releasing activity induced by PD homogenate. © 1989 Birkhäuser Verlag.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
