Methoxychlor (MXC) is an organochlorine pesticide that reduces fertility in female rodents by decreasing antral follicle numbers and increasing follicular death. MXC is metabolized in the body to mono-hydroxy MXC (mono-OH). Little is known about the effects of mono-OH on the ovary. Thus, this work tested the hypothesis that mono-OH exposure decreases production of 17β-estradiol (E2) by cultured mouse antral follicles. Antral follicles were isolated from CD-1 mice (age 35-39days) and exposed to dimethylsulfoxide (DMSO), or mono-OH (0.1-10μg/mL) for 96h. Media and follicles were collected for analysis of sex steroid levels and mRNA expression, respectively. Mono-OH treatment (10μg/mL) decreased E2 (DMSO: 3009.72±744.99ng/mL; mono-OH 0.1μg/mL: 1679.66±461.99ng/mL; 1μg/mL: 1752.72±532.41ng/mL; 10μg/mL: 45.89±33.83ng/mL), testosterone (DMSO: 15.43±2.86ng/mL; mono-OH 0.1μg/mL: 17.17±4.71ng/mL; 1μg/mL: 13.64±3.53ng/mL; 10μg/mL: 1.29±0.23ng/mL), androstenedione (DMSO: 1.92±0.34ng/mL; mono-OH 0.1μg/mL: 1.49±0.43ng/mL; 1μg/mL: 0.64±0.31ng/mL; 10μg/mL: 0.12±0.06ng/mL) and progesterone (DMSO: 24.11±4.21ng/mL; mono-OH 0.1μg/mL: 26.77±4.41ng/mL; 1μg/mL: 20.90±3.75ng/mL; 10μg/mL: 9.44±2.97ng/mL) levels. Mono-OH did not alter expression of Star, Hsd3b1, Hsd17b1 and Cyp1b1, but it did reduce levels of Cyp11a1, Cyp17a1 and Cyp19a1 mRNA. Collectively, these data suggest that mono-OH significantly decreases levels of key sex steroid hormones and the expression of enzymes required for steroidogenesis.
- Antral follicles
ASJC Scopus subject areas