FSH and LH enhance the development of goat preantral follicles cultured in vitro

This study evaluated the effect of increased follicle stimulating hormone (FSH) concentrations on the expression of mRNA for LH receptors after in vitro culture of goat preantral follicles (>= 150 mu m) for 18 days. It also investigated whether the addition of luteinizing hormone (LH) to the culture medium, which contained increasing concentrations of FSH throughout the culture period, influenced the survival, growth and antrum formation of in vitro cultured goat preantral follicles. In experiment 1, preantral follicles were cultured in alpha-MEM+ or alpha-MEM+ supplemented with increasing concentrations of FSH throughout the culture period (sequential medium: FSH 100 ng/ml (days 0 to 6), FSH 500 ng/ml (days 6 to 12) and FSH 1000 ng/ml (days 12 to 18). The expression of luteinizing hormone receptor (LHR) was analyzed in noncultured and cultured follicles using real time RT-PCR. In experiment 2, isolated preantral follicles were cultured for 18 days in a sequential medium containing FSH (control) or a control medium supplemented with LH (50 or 100 ng/ml) from day 12 of culture onwards. Follicle development was evaluated on the basis of antral cavity formation as well as follicular and oocyte growth after in vitro maturation. FSH stimulated a significant increase in the expression of mRNA for LH receptors after 18 days of culture. Furthermore, after 18 days, all tested media promoted follicular survival and antrum formation; however, a significant increase in the rate of follicular growth and resumption of meiosis was observed when LH was used compared to the control. In conclusion, preantral follicles cultured in a medium supplemented with FSH increased LH receptor mRNA levels. Moreover, the addition of LH to the culture medium containing increasing concentrations of FSH (sequential medium) improved the in vitro development of goat preantral follicles.