Efeito do hormônio folículo estimulante (FSH) e da melatonina sobre o cultivo e a maturação in vitro de folículos ovarianos pré-antrais e antrais

Abstract

The effect of human recombinant follicle stimulating hormone (rhFSH) and melatonin on culture and in vitro maturation of ovine follicles was evaluated. This work was divided into 3 Chapters. Chapter I: Secondary follicles were cultured in α-MEM+ (control) or added at different fixed concentrations (500, 750 and 1000 ng/mL) or sequential concentrations of rhFSH (Seq.1 and Seq.2). Secondary follicles (Chapter II) and initial anthraxes (Chapter III) were cultured using different fixed concentrations of melatonin (Mel 100, Mel 500 or Mel 1000 pg/mL) or a sequential concentration (Mel Seq). Cap.I: follicular survival was higher in rhFSH 750 ng/mL than in α-MEM+ and 1000 ng/mL. The addition of rhFSH in the medium promoted a significant increase in the percentage of fully grown oocytes in all treatments compared to α-MEM+. Mitochondrial activity was higher in rhFSH treatments than control, except rhFSH Seq. 2. Following IVM, intact follicular oocytes cultured in rhFSH 750 ng/mL showed a significant increase in maturation percentage compared to α-MEM+. Cap.II: Mel 500 pg/mL and Mel 1000 pg/mL showed a significantly higher rate of fully grown oocytes than the other treatments. After the IVM, ERO levels were lower in Mel 1000 pg / mL compared to the other treatments. Cap III: Honey 500 pg/mL presented higher rate of fully grown oocytes in vitro than the other treatments. After IVC, the levels of ROS in the oocyte were similar between Mel 500 pg/mL and MelSeq, both being lower than the other treatments. Mitochondrial activity was similar between control treatments, Mel 500 and 1000 pg/mL. Mel 500 pg/mL presented a higher percentage of GVBD oocytes than the control group and percentages similar to the others. Follicles cultured in melatonin followed by oocyte maturation with addition of 500 pg/mL melatonin in the IVM medium showed increased mitochondrial activity than α-MEM+. After the results obtained, it can be inferred that using a defined medium, FSH at a concentration of 750 ng/mL maintains follicular survival and promotes an increase in active mitochondria levels, growth and improvement of oocyte maturation. In addition, it was possible to demonstrate that melatonin in the culture of preantral and antral follicles can increase oocyte energetic levels, reduce the production of reactive oxygen species and favor the production of oocytes of appropriate size for in vitro maturation.