the second group , consisting of the lh-stimulated reduced progesterone metabolites , 5 alpha-pregnane-3,20-dione ( pregnanedione ) and 20 alpha-hydroxy-pregn-4-en-3-one ( dihydroprogesterone ) , tended to inhibit serum gonadotrophin levels as well as inhibiting the pro-oestrous increase of [ 35s ] incorporation in the median eminence area and in the amygdala , but not in the preoptic area and the anterior pituitary .
C0033308
progesterone
C0012311
dihydroprogesterone