In vivo and in vitro Ovarian Steroidogenesis in the Pregnant Rat

Abstract
The interrelationship between follicular and luteal function during pregnancy in the rat was examined by in vivo and in vitro methods. Corpora lutea (CL) and nonluteal ovarian tissues (NLO) were removed on Days 2 to 22 (at 2 day intervals) (day sperm-positive = Day 1 of pregnancy), and incubated separately for 2 h to determine the production rate of steroids. Changes in progesterone (P), 20α-dihydroprogesterone (20α-OHP), testosterone (T), and estradiol-17β (E2) in peripheral blood, CL, and NLO, and levels of LH and FSH in serum and pituitary were measured by radioimmunoassay.