PGF 2α, PGE 2, prosgesterone, and estradiol-17β, secretion by the corpus luteum of the oviparous lizard, Podarcis sicula sicula. In vitro studies

Abstract

The release in vitro of prostaglandin F 2α (PGF 2α), prostaglandin E 2 (PGE 2), progesterone, androgens and estradiol-17β by the corpora lutea (CL) of the oviparous lizard, Podarcis s. sicula, was studied. In addition, the in vitro effects of PGF 2α and PGE 2 on sex steroid release by CL were evaluated. Corpora lutea were divided into four types, according to their different developmental stage: CL1 (unshelled eggs in the oviduct); CL2 (shelled eggs in the oviduct); CL3 (eggs laid 6 h previously); CL4 (eggs laid 48 h previously) and were placed into culture. PGF 2α secretion was highest in CL4 incubated samples and lowest in CL2 and PGE 2 was highest in CL1 and CL2. Progesterone secretion was highest in CL2 and lowest in CL4; androgens were not detectable and estradiol-17β secretion was highest in CL2. PGF 2α decreased progesterone secreted by CL1, CL2 and CL3, while it did not modify release of androgens and estradiol-17β. PGE 2 did not affect sex steroid release. These data suggest a role of PGF 2α in inducing luteolysis, while PGE 2 could be implied in the maintenance of CL. A role of progesterone during gestation of Podarcis s. sicula was also confirmed.