A. Gobbetti et al., PROSTAGLANDINS AND CORTICOSTERONE IN THE OVIPAROUS FEMALE LIZARD, PODARCIS-SICULA-SICULA, DURING REPRODUCTION, Acta Physiologica Scandinavica, 153(3), 1995, pp. 301-308
The in vitro effects of prostaglandin F-2 alpha (PGF(2 alpha)) and pro
staglandin E(2) (PGE(2)) on corticosterone release by ovarian follicle
s, corpora lutea (CL), and interrenaIs were studied in the female liza
rd, Podarcis sicula sicula, during reproduction. Follicles and CL were
divided according to their different developmental stages; follicles:
previtellogenic, early-vitellogenic, mid-vitellogenic and fully-grown
; CL: CL1 (unshelled eggs in the oviducts), CL2 (shelled eggs in the o
viducts), CL3 (eggs laid 6 h previously) and CL4 (eggs laid 48 h previ
ously). Interrenals were divided according to the reproductive stages:
pre-vitellogenesis, vitellogenesis, ovulation, post-ovulation, and po
st-deposition. PGF(2 alpha) release was highest in fully-grown follicl
es and PGE(2) in early-vitellogenic follicles, corticosterone was high
est in pre-viteliogenic and lowest in early-vitellogenic follicles. PG
E(2) decreased corticosterone in pre-vitellogenic, mid-vitellogenic an
d fully-grown follicles. PGF(2 alpha) release was highest in CL4, and
PGE(2) in CL1 and CL2, corticosterone was highest in CL4. PGF(2 alpha)
increased corticosterone in CL1, CL2 and CL3. In interrenals, PGF(2 a
lpha) release was highest and PGE(2) lowest during ovulation, corticos
terone was highest during ovulation. PGF(2 alpha) increased and PGE(2)
decreased interrenal corticosterone during vitellogenesis, ovulation,
and post-ovulation. In the plasma, PGF(2 alpha) levels were highest a
nd PGE(2) lowest during ovulation, corticosterone was highest during o
vulation. These results suggest that corticosterone, modulated by PGF(
2 alpha) and PGE(2), is implied in the reproductive processes with dif
ferent roles. In fact this steroid could favour ovulatory and luteolyt
ic processes. In addition the hypothesis of an anti-vitellogenic role
of corticosterone is discussed.