INFLUÊNCIA DE HORMÔNIOS E LÍQUIDO FOLICULAR NA MATURAÇÃO DE OÓCITOS SUÍNOS

To evaluate the effect of follicular fluid on in vitro maturation, pig oocytes were cultured in the presence of hormones where 10% of fetal calf serum (FCS), 10% of follicular fluid from large follicles (l-pFF), 10% of follicular fluid from medium follicles (m-pFF) or no supplement were added. When oocytes where matured in medium containing the hormones the addition of different supplements did not affect (P<0.05) nuclear maturation. However, changing the supplement altered the cytoplasmic maturation, with higher rate (P<0.05) observed in the l-pFF group. To determine the effect of the presence of hormone and/or supplement during maturation, the oocytes were cultured either in presence of TCM-199 alone, with hormones, with 10% l-pFF or with hormones and 10% l-pFF. The highest proportion of oocytes undergoing nuclear and cytoplasmic maturation was obtained when both hormones and follicular fluid were present. Cumulus expansion had a significant (P<0.05) effect on cytoplasmic maturation with the non-expanded groups showing a lower percentage of maturation in all groups. When the adequacy of gonadotropins levels were evaluated by adding higher or lower concentrations into the maturation medium neither beneficial nor detrimental effects were observed in either nuclear or cytoplasmic maturation. These results suggest that changes in the composition of the medium can alter the percentage of oocytes completing maturation. Follicular fluid combined with hormones was found to give better conditions for pig oocyte maturation in vitro.O presente estudo avaliou o efeito da presença do líquido folicular e hormônios durante a maturação nuclear e citoplasmática em ovócitos suínos. Para avaliar o efeito do líquido folicular, os oócitos foram maturados in vitro em TCM-199 na presença de hormônios, em que o meio foi suplementado com 10% de soro fetal bovino (SFB), 10% de líquido folicular de folículos grandes (l-pFF), 10% de líquido folicular de folículos médios (m-pFF) ou nenhum suplemento. Quando os oócitos foram maturados no meio contendo hormônios, a adição de diferentes suplementos não afetou (P<0,05) a maturação nuclear. Entretanto, mudanças no suplemento provocaram uma alteração na maturação citoplasmática, sendo que as maiores taxas (P<0,05) foram observadas no grupo com l-pFF. Para determinar o efeito da presença de hormônios e/ou suplemento durante a maturação, os oócitos foram cultivados em TCM-199, TCM-199 com hormônios, TCM-199 com 10% l-pFF ou TCM-199 com hormônio e 10% l-pFF. A maior proporção de oócitos que sofreram maturação nuclear e citoplasmática ocorreu no grupo em que ambos, hormônios e líquido folicular, estavam presentes. A expansão do cumulus influenciou (P