PROSTAGLANDIN-E2 AND PROSTAGLANDIN-F2-ALPHA INVOLVEMENT IN THE CORTICOSTERONE AND CORTISOL RELEASE BY THE FEMALE FROG, RANA-ESCULENTA, DURING OVULATION
A. Gobbetti et M. Zerani, PROSTAGLANDIN-E2 AND PROSTAGLANDIN-F2-ALPHA INVOLVEMENT IN THE CORTICOSTERONE AND CORTISOL RELEASE BY THE FEMALE FROG, RANA-ESCULENTA, DURING OVULATION, The Journal of experimental zoology, 267(2), 1993, pp. 164-170
Interrenal and ovarian tissues of Rana esculenta were incubated in vit
ro during the preovulatory, ovulatory and postovulatory phases to stud
y the basal release of prostaglandin E2 (PGE2), prostaglandin F2alpha
(PGF2alpha), corticosterone, and cortisol. The effects of exogenous PG
E2 and PGF2alpha on interrenal and ovarian corticosteroid release were
also studied. In addition, the plasma values of these four hormones w
ere assessed during the same phases. During in vitro interrenal incuba
tions, PGE2, PGF2alpha, corticosterone, and cortisol basal releases we
re higher in the postovulatory phase, PGE2 and PGF2alpha treatment in
vitro increased corticosteroids during the ovulatory phase. During in
vitro ovarian incubations, PGE2 basal release was higher in the preovu
latory phase and PGF2alpha and corticosteroids in the ovulatory phase;
PGE2 treatment in vitro decreased corticosteroids in the ovulatory ph
ase, and PGF2alpha increased corticosteroids in the preovulatory and p
ostovulatory phases. PGE2, corticosterone and cortisol plasma values w
ere higher during the postovulatory phase, while PGF2alpha was elevate
d during the ovulatory phase. These findings suggest that ovarian cort
icosteroids could be considered one of the factors inducing ovulation
and that their synthesis may be modified by PGs. (C) 1993 Wiley-Liss,
Inc.