Av. Sirotkin et al., DIRECT ACTION OF LH RH AND ITS ANTAGONIST ON ISOLATED BOVINE GRANULOSA-CELLS STEROIDOGENESIS, Journal of endocrinological investigation, 17(9), 1994, pp. 723-728
Progesterone, 4-androstene-3,17-dione, testosterone and estradiol-17 b
eta secretion by bovine granulosa cells culture without or in the pres
ence of 10, 100 or 10.000 ng/ml LH RH or of its antagonist (D Phe2, D
Phe6) LH RH were analyzed. It was observed that both LH RH and its ant
agonist significantly activated progesterone and estradiol output. LH
RH also stimulated, but (D Phe2, D Phe6) LH RH inhibited granulosa 4-a
ndrostene-3,17-dione secretion. Both LH RH and its analogue decreased
testosterone release by the cell culture. This is the first demonstrat
ion of a direct influence of LH RH on bovine ovarian steroidogenesis.
The lack of correlation between LH RH and its agonist action on hypoph
ysis and on different gonadal steroids secretion may suggest the diffe
rences in the features of receptors to LH RH -related peptides in the
various target cells.