PLOD1 and polycystic ovary syndrome: By weakening the negative effect on LH production in the pituitary, the loss of estrogen leads to higher levels of LH, which further stimulate theca cells to release T. Letrozole is typically given orally to six-week-old female rats (puberty) at dosages of 0.1, 0.5, and 1 mg/kg daily for 21 days, after which they become acyclic and exhibit biochemical and histological characteristics of human PCOS.