Background: Main function of corpus luteum is progesterone synthesis
that is significantly accompanied with an increase in levels of mRNA
encoding of steroidogenic enzymes known as luteal markers. Objective:
This study was designed to evaluate effects of lithium chloride on the
release of steroid hormones and steroidogenic enzymes in
gonadotropin-stimulated rats. Materials and Methods: Immature 23 days
old Wistar rats were divided into 10 groups; each group comprised of 8
rats, and induced with single injection of pregnant mare’s serum
gonadotrophin (PMSG) and followed by single injection of human
chorionic gonadotropin (hCG). Then, rats were given lithium chloride
(LiCl) or saline at 12 hours post-hCG injection. Ovaries were collected
in 4-hour interval from 8-24 hour post-hCG injection. Expression
pattern of steroidogenic acute regulatory protein (StAR), side-chain
cleavage cytochrome P450 (P450scc) and 3β-hydroxysteroid
dehydrogenase (3β-HSD) genes were determined by semi-quantitative
RT-PCR. In addition, serum levels of progesterone and
17β-estradiol were measured by ELISA. Results: Our results showed
that hCG stimulation of progesterone was markedly diminished and
transcript levels of key steroidogenic enzymes were altered in the
hormone-stimulated rats following LiCl treatment. Conclusion: These
results suggest that critical steps in the function of corpus luteum
are disrupted by lithium. It is concluded that LiCl is an effective
factor for suppressing of steroid genes expression