Changes in ovarian follicles and in vitro sex hormone release in the lizardPodarcis sicula sicula (original) (raw)

1993, Molecular Reproduction and Development

An rn vrtro superfusron method was used to test sex hormone release from drfferent krnds of ovanan folhcle (growrng folhcles, postovulatory folhcles, and atretlc folhcles) rn the ltzard Podaras stcula srcula. Sex hormone output changes wrth the stage of follrcle evolutron and sexual cycle. Prevtellogenetrc folhcles prevarl rn earlyspnng qurescent ovanes and secrete marnly progesterone, whrch rs probably utrhzed at that phase to delay ovanan resumptton. In the actrve ovary, progesterone output from prevrtellogenetrc folhcles decreases, whereas vrtellogenetrc folhcles produce a srgnfrcant amount of l7B-estradrol, whrch rs necessary for sustarnrng vrtellogenrn synthesrs by the lruer and ovrduct growth. As folhcles become npe, progesterone productron ts resumed, and t rncreases In young postovulatory folhcles. Thrs rs rn hne wth the functrons assrgned to the hormone at that phase of the sexual cycle, r.e., the rnductron of oocyte maturatron and the regulatron of egg retentron rn the ovrduct. Postovulatory folhcles can also synthetrze 17B-estradrol After ovtposrtron, thrs hormone, whrch rs secreted by the old postovulatory folhcles, can rernft rate vrtellogen In synthesrs, al lowr ng the development of a new oocyte set. Our data confrrm that acttve, although ephemeral, corpora lutea are also formed ln ouparous specres. A hmrted contrrbutron to ovarran sex sterord productton denves also from atrettc folltcles, at least at the early stages of the breedrng cycle. O 1993 Wrley-Lrss. Inc