Effect of melatonin on the c-fos gene expression in suprachiasmatic nuclear of mice

AIM: To observe the c-fos gene expression in the suprachiasmatic nuclear (SCN) of mice after melatonin (MEL) treatment under normal and light-dark shifting circumstances. METHOD: c-fos production was determined by the immuno-histochemical staining with the anti-murine c-fos antibody; A region selective RNA extraction and rapid RT-PCR method was used to analyse mRNA level in the SCN. RESULTS: The levels of c-fos protein and mRNA in the young mice were higher than those in the old mice. In the light-dark shifting (L:D 14:10, alternating every 3 days), both the levels of c-fos protein and mRNA in each group were decreased. MEL was found to enhance their expression. CONCLUSION: c-fos expression is down regulated along with aging, Light-dark shifting inhibits its expression, MEL(sc) administration can stimulate c-fos expression even under the aging and light-dark shifting conditions, Indicating that MEL might exert its anti-aging effects through increasing c- fos gene expression.