Ascorbic acid improves the survival and in vitro growth of isolated caprine preantral follicles
G.M. Silva, V.R. Araújo, A.B.G. Duarte, R.N. Chaves, C.M.G. Silva, C.H. Lobo, A.P. Almeida, M.H.T. Matos, L.M.T. Tavares, C.C. Campelo, J.R. Figueiredo
Anim Reprod, vol.8, n1/2, p.14-24, 2011
The present study aims to investigate the influence of two concentrations of ascorbic acid on the survival, growth, antral formation and mRNA expression of the matrix metalloproteinases-9 (MMP-9) and their tissue inhibitor-2 (TIMP-2) on caprine preantral follicles during long-term in vitro culture. Isolated preantral follicles were individually cultured without or with ascorbic acid at 50 µg/ml (AA50) or 100 µg/ml (AA100) during 18 days. The parameters evaluated were follicular viability, growth, antrum formation and extruded oocytes. The genes MMP-9 and TIMP-2 were quantified by real-time polymerase chain reaction (qPCR) after 18 days of culture in the control medium (MEM+ ) or ascorbic acid (50 or 100 µg/ml) and in fresh control (non cultured). At the end of culture, AA50 significantly increased the percentage of viable follicles compared with other treatments. Moreover, mean daily increase in follicular diameter (µm/day) was significantly higher in the presence of both concentrations of ascorbic acid than in MEM+ alone. Higher rates of antral formation and lower percentages of extruded oocytes were observed in medium containing AA50 compared with control medium. Real Time RT-PCR assays showed that AA50 increases MMP-9 expression significantly compared with fresh control and MEM+ alone. In conclusion, ascorbic acid at 50 µg/ml was very important for the maintenance of caprine preantral follicle viability and development after in vitro culture and influences in vitro the enzymes involved with basement membrane remodeling.
caprine, culture, MMP-9, preantral follicles, TIMP-2