LAUSR

The aims of the study were to characterize leptin and it is receptor (LEPR) proteins immunoexpression in ovine ovaries and to evaluate the effects of leptin on development of secondary follicles cultivated in vitro. The ovaries were collected and fixed for immunohistochemical analysis. Additional pairs of ovaries were collected and secondary follicles were isolated and cultured, for 18 days, in α-MEM+ alone or supplemented with 10 or 25 ng/mL of leptin. The antrum formation and fully grown oocytes rates were higher in 25 ng/mL leptin compared to all treatments. GSH levels and mitochondrial activity were higher in 10 or 25 ng/mL leptin compared to α-MEM+. 25 ng/mL leptin showed a higher percentage of MII than the α-MEM+. In conclusion, leptin and its receptor are express in ovine ovaries and 25 ng/mL leptin promoted higher in vitro maturation rates by improving follicular development, GSH levels and mitochondrial activity of ovine oocytes compared to control medium.