Endocrine Abstracts

Cystic ovarian disease is a common reproductive disorder in women and females of domestic animals, leading to temporal or permanent infertility. Over one in three women with polycystic ovarian syndrome (PCOS) are overweight and have higher serum leptin concentration. Leptin may thereby mediate some of the adverse effect of obesity on ovarian function.

In the presented data, we decided to compare the action of two high doses of leptin (20 ng and 40 ng/ml) on progesterone (P₄), androstenedione (A₄), testosterone (T) and estradiol (E₂) secretion by small- and medium-sized follicles collected from pubertal and cycling pig. Taking into consideration previously published data reported that alterations in the content of steroid hormones in the cystic ovaries of swine was accompanied by changes in the expression and cellular distribution pattern of steroidogenic enzymes we evaluated action of leptin on CYP11A1, CYP17, 17β-HSD and CYP19 protein expression by western blot. During prepubertal time, leptin in both doses had no effect on steroids secretion by medium-size follicles, why increased P₄ and testosterone secretion with concomitant decrease in A₄ secretion and no effect on E₂ secretion by small size follicles. It was accompanied by increasing the expression of CYP11A1 in both size of follicles and 17 β-HSD in small follicles. In cycling animals, increase in P₄ and testosterone secretion with concomitant decrease in A₄ secretion and no effect on E₂ secretion by small and medium size follicles was noted. It was accompanied by increasing the expression of CYP11A1 and 17 β-HSD in both size of follicles.

These results suggested that leptin by action on above-mentioned enzymes, and influencing the ovarian steroid synthesis, may play an essential role in the creation and/or course of cystic ovarian disease both in prepubertal and regular cycling animals.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however, funding details unavailable.