Ovarian morphometry and mRNA expression of antimüllerian hormone (AMH), follicle stimulating hormone receptor (FSHR) and nuclear factor kappa B (NFkB) in growing follicles of female lambs prenatally exposed to testosterone

Abstract

Antenatal exposure to testosterone (T) has a series of consequences on postnatal reproductive parameters in females of several animal species. In sheep born under this condition the ovaries are characterized by an increased number of growing follicles. If such disruptions are manifested early in life or involve changes in follicular recruitment and ovary paracrine environment, it remains unclear. This study addressed the impact of prenatal T on ovarian morphometry and the mRNA expression of ovarian anti-müllerian hormone (AMH), FSH receptor (FSHR) and nuclear factor kappa B (NFkB, a transcription factor for AMH), factors that are involved in the growth and selection of the dominant follicle. At 4 weeks of age, female lambs born to dams treated with 30 mg of T propionate twice weekly from day 30 to day 90, followed by 40 mg of T propionate from day 90 to day 120 of pregnancy (T females), showed similar number of primordial, primary, secondary and antral follicles than control females (C females) born to dams treated with the vehicle. In the pool of secondary follicles (< 0.5 mm) the expression of the FSHR was slightly higher in the T females, while AMH and NFkB expression were lower than C females. Instead, the pool of small antral follicles (between 0.5 and 1 mm) showed a higher expression of FSHR and a slight increase in AMH in T females, while NFkB expression remained lower than C females. These findings provide evidence that the prenatal exposure to T impacts the expression of key local factors governing the folliculogenesis before histological alterations occur.