Estradiol 17-beta is known to induce hepatic synthesis and secretion of vitellogenin in all species studied and in Rana esculenta, previous experiments demonstrated the involvement of pituitary in these processes; indeed, in addition to estradiol 17-beta, homologous pituitary homogenate directly stimulated male and female liver to produce vitellogenin in tissue cultures. Therefore, the effect of ovine growth hormone (o-GH) and Rana catesbeiana growth hormone (f-GH) on hepatic vitellogenin synthesis was investigated. In the present in vitro experiments, both o-GH and f-GH positively stimulated vitellogenin synthesis, in female and male liver, in a dose-related fashion. No significant differences were found in VTG levels induced by o-GH and f-GH. The GH stimulatory effects, found during the different phases of the reproductive cycle, displayed different trends related to season and sex.
Hormonal control of in vitro vitellogenin synthesis in Rana esculenta liver: effects of mammalian and amphibian growth hormone
CARNEVALI, Oliana;MOSCONI, Gilberto;POLZONETTI, Alberta Maria
1992-01-01
Abstract
Estradiol 17-beta is known to induce hepatic synthesis and secretion of vitellogenin in all species studied and in Rana esculenta, previous experiments demonstrated the involvement of pituitary in these processes; indeed, in addition to estradiol 17-beta, homologous pituitary homogenate directly stimulated male and female liver to produce vitellogenin in tissue cultures. Therefore, the effect of ovine growth hormone (o-GH) and Rana catesbeiana growth hormone (f-GH) on hepatic vitellogenin synthesis was investigated. In the present in vitro experiments, both o-GH and f-GH positively stimulated vitellogenin synthesis, in female and male liver, in a dose-related fashion. No significant differences were found in VTG levels induced by o-GH and f-GH. The GH stimulatory effects, found during the different phases of the reproductive cycle, displayed different trends related to season and sex.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.