RESUMO
A sequential medium was evaluated on the survival, activation and growth rates of caprine preantral follicles submitted to a long-term culture period, aiming to establish an ideal in vitro culture system. Ovarian fragments were cultured for 16 days in α-MEM(+) alone or supplemented with hormones (GH and/or FSH) added sequentially on different days of culture. Ovarian fragments were cultured in the first (days 0-8) and second (days 8-16) halves of the culture period, generating 10 treatments: α-MEM(+)/α-MEM(+), FSH/FSH, FSH/GH, FSH/FSH+GH, GH/GH, GH/FSH, GH/FSH+GH, FSH+GH/FSH+GH, FSH+GH/FSH and FSH+GH/GH. Follicle morphology, viability and ultrastructure were analyzed. After day 1 of culture, FSH treatments maintained the percentage of normal follicles similar to the fresh control. At day 16 of culture, the treatment FSH/GH showed the highest (P<0.05) percentage of normal follicles. The ultrastructure of follicles was preserved in the fresh control and FSH/GH treatment. Follicles cultured with FSH/GH had a higher (P<0.05) viability than α-MEM(+); however the viability was lower (P<0.05) when compared to the fresh control. The FSH/GH treatment showed the highest (P<0.05) percentage of follicular activation and secondary follicle formation and produced the largest (P<0.05) mean follicular diameter after 16 days of culture. In conclusion, a sequential medium supplemented with FSH followed by GH during a long-term culture maintains the survival, viability and ultrastructure of goat preantral follicles, and promotes activation and secondary follicles.
Assuntos
Cabras/fisiologia , Ovário/efeitos dos fármacos , Ovário/fisiologia , Técnicas de Cultura de Tecidos/veterinária , Animais , Meios de Cultura , Feminino , Hormônio Foliculoestimulante/farmacologia , Hormônio do Crescimento/farmacologia , Ovário/ultraestrutura , Fatores de TempoRESUMO
A foliculogênese é caracterizada pelo desenvolvimento folicular, envolvendo as etapas de ativação, crescimento e maturação. Durante este evento, hormônios e fatores de crescimento agem em conjunto controlando os complexos mecanismos envolvidos na fisiologia reprodutiva. Dentre estes, destacam-se o hormônio do crescimento (GH) e o fator de crescimento semelhante à insulina I (IGF-I), que estão presentes nas diversas etapas da foliculogênese, atuando de forma direta e/ou indireta a fim de proporcionar o desenvolvimento folicular. Durante as últimas décadas, pesquisas acerca do efeito destas substâncias, isoladas ou em associação, têm sido amplamente realizadas. Neste sentido, esta revisão irá abordar o papel do GH e do IGF-I na regulação da foliculogênese, bem como a interação destes fatores nos desenvolvimentos foliculares in vivo e in vitro.(AU)
The folliculogenesis is characterized by follicular development, involving the steps of activation, growth and maturation. During this event, hormones and growth factors act jointly managing the complex mechanisms involved in reproductive physiology. Among these, we highlight the Growth Hormone (GH) and Insulin-like Growth Factor I (IGF-I) that are present at different stages of folliculogenesis, acting in ways direct or indirect to provide follicular development. During recent decades, searches on the effect of these substances alone or in combination have been widely performed. Therefore, this review will address the role of GH and IGF-I in regulation of folliculogenesis, as well as the interaction of these factors in follicular development in vivo and in vitro.(AU)
Assuntos
Animais , Hormônio do Crescimento/análise , Hormônio do Crescimento/química , Fator de Crescimento Insulin-Like I/análise , Folículo Ovariano/embriologia , Hormônio Luteinizante/química , Hormônio FoliculoestimulanteRESUMO
A foliculogênese é caracterizada pelo desenvolvimento folicular, envolvendo as etapas de ativação, crescimento e maturação. Durante este evento, hormônios e fatores de crescimento agem em conjunto controlando os complexos mecanismos envolvidos na fisiologia reprodutiva. Dentre estes, destacam-se o hormônio do crescimento (GH) e o fator de crescimento semelhante à insulina I (IGF-I), que estão presentes nas diversas etapas da foliculogênese, atuando de forma direta e/ou indireta a fim de proporcionar o desenvolvimento folicular. Durante as últimas décadas, pesquisas acerca do efeito destas substâncias, isoladas ou em associação, têm sido amplamente realizadas. Neste sentido, esta revisão irá abordar o papel do GH e do IGF-I na regulação da foliculogênese, bem como a interação destes fatores nos desenvolvimentos foliculares in vivo e in vitro.
The folliculogenesis is characterized by follicular development, involving the steps of activation, growth and maturation. During this event, hormones and growth factors act jointly managing the complex mechanisms involved in reproductive physiology. Among these, we highlight the Growth Hormone (GH) and Insulin-like Growth Factor I (IGF-I) that are present at different stages of folliculogenesis, acting in ways direct or indirect to provide follicular development. During recent decades, searches on the effect of these substances alone or in combination have been widely performed. Therefore, this review will address the role of GH and IGF-I in regulation of folliculogenesis, as well as the interaction of these factors in follicular development in vivo and in vitro.