Abstract: Estrogens play essential roles in the neuroendocrine control of reproduction. To simulate inhibiting effects of GnRH secretion and GnRH-related genes(GnRH, ERα, KISS-1 and GPR54) expression by estrogens in vitro, the GnRH-secreting neuronal cell line GT1-7 was exposed to 1 μmol/L estradiol concentrations for 0, 6, 12, 18, 24 and 30 h, respectively. The result showed that GnRH secretion of GT1-7 cells treated with 1 μmol/L 17β-estradiol was decreased significantly(18 and 30 h, P<0.01), although slightly increased(6 and 12 h, P>0.05) at the beginning of the process. Compared with the control, GnRH mRNA treated with 1 μmol/L estradiol was significantly decreased(P<0.01) through all culture period. ERα(12 and 18 h, P<0.01), KISS-1(12 h, P<0.01) and GPR54(6, 12 and 24 h, P<0.01) mRNA were also decreased. It revealed that 1 μmol/L estradiol could inhibit GnRH secretion of GT1-7 cells and this effect may be achieved by down-regulating mRNA of ERα, KISS-1, GnRH and GPR54.

Key words: 17β-estradiol, GT1-7, GnRH, gene expression