nuclear and cytoplasmic exchange assays were utilized to quantify receptors for estradiol-17 beta ( e2 ) and progesterone ( p4 ) in hypothalamic and pituitary tissues from 4-6 gilts each on days 1 , 5 , 10 , 15 and 18 of the estrous cycle and from 4-5 gilts each on days 5 , 10 , 15 , 21 and 30 of pregnancy .
C0033308
progesterone
C0032961
pregnancy