Allopregnanolone Alters the Luteinizing Hormone, Prolactin, and Progesterone Serum Levels Interfering with the Regression and Apoptosis in Rat Corpus Luteum

MYRIAM R. LACONI; CANDELARIA CHAVEZ; JUAN C. CAVICCHIA ; MABEL FÓSCOLO ; ZULEMA SOSA; ROBERTO F. YUNES; RICARDO J. CABRERA

HORMONE AND METABOLIC RESEARCH

GEORG THIEME VERLAG KG

Año: 2012 vol. 44 p. 632 - 643

0018-5043

Abstract ▼ Steroids synthesized in the central nervous system are termed ?neurosteroids?. They are synthesized and metabolized in several brain areas.The objective of this work was to determine if 1 intracerebroventricular allopregnanolone injection in rats can interfere in luteal regression in a close relationship with modifi cations in LH, progesterone,and prolactin serum concentrations. Allopregnanolone was injected during proestrus morning and the animals were sacrifi ced on oestrous morning. Ovulation test and histological analysis were performed in the oestrus morning with light and electron microscopy. Serum prolactin, LH, and progesterone levels were measured by radioimmunoassay. The allopregnanolone injection signifi cantly decreased luteinizing hormone serum level and the number of oocytes on oestrus. Progesterone and prolactin serum levels were increased after this injection.The inhibition of apoptotic fi gures due to allopregnanolone administration was detected in the already formed corpora lutea belonging to the previous ovary cycle and it was significantly lower than in vehicle group (control). When the GABA A antagonist (bicuculline) was administered alone or previously to allopregnanolone, no eff ect on the ovulation rate was observed.No changes in the apoptotic cell numbers were observed with respect to those of vehicle group .These results show that the eff ect of centrally injected allopreganolone over reproductive function could be due to a centrally originated LH mediated eff ect over ovarian function that affects luteal regression, through the inhibition of apoptosis and stimulation of progesterone and prolactin release.