Abstract: Objective To investigate the effects of fulvestrant inducing apoptosis of pituitary adenoma GH3 cells and the acute toxicity of fulvestrant on mice. Methods After treated with fulvestrant for 72 h, the proliferative activity of pituitary adenoma GH3 cells was determined by MTS assay and 50% inhibitory concentration (IC50). Simultaneously, the apoptosis ratios of pituitary adenoma GH3 induced by fulvestrant were detected by Annexin V-FITC/PI. The acute oral toxicity of fulvestrant in mice was used by the maximum limit method. The mice were observed daily to record the number of death and body weight, then 50% lethal dose (LD50) was counted. Pathological examination was competed at the end of the 14 d observation period. Results The IC50 of fulvestrant on pituitary adenoma GH3 cells was 361.9 nM. Fulvestrant could induce apoptosis of GH3 cells dose-dependently. There were no death mice in the 14 d acute oral toxicity test which means the LD50 was greater than 2 000 mg·kg-1. The fetal tissue of mice was found that there was no significant difference between the blank group and the fulvestrant treatment group according to the histopathology observation. Conclusion Fulvestrant induces apoptosis of pituitary adenoma GH3 cells. The acute toxicity of fulvestrant is low and the LD50 was greater than 2 000 mg·kg-1 which indicates that fulvestrant is safe.

Key words: fulvestrant, pituitary adenoma, acute toxicity, apoptosis