Résumé
OBJECTIVE: To investigate the effect of bromocriptine on the expression of Pit-1 in prolactinoma rats. METHODS: Firstly, to prepare prolactinoma model in rats. Adult Wistar rats were divided into two groups at random. The rats in control group were subscutaneously implanted with a blank implant. Rats in 17β-estradiol group were implanted with 17β-estradiol-containing implants. Secondly, rates in 17β-estradiol group were divided into two groups at random: model group and bromocriptine group. Water was administrated to rats in model group. Bromocriptine (0.225 mg · kg-1 · d-1) were orally administrated to rats in bromocriptine group, the rats in control group were orally administrated with water. After four weeks of treatment, all the animals were executed. Each pituitary gland was weighed. Serum prolactin (PRL) levels were measured by RIA method. Pit-1 mRNA levels in pituitaiy tissue were measured by RT-PCR method. RESULTS: The weights of pituitary gland and PRL levels in 17β-estradiol group were individually higher than those in control group (P<0.001). The expression levels of Pit-1 mRNA in bromocriptine group was obviously lower than that in model group (P≤0.001). CONCLUSION: Bromocriptine has potential preventive effect to estrogen-induced rat prolactinoma. The decrease of Pit-1 mRNA level may be involved in the mechanism of anti-prolactinoma effect of bromocriptine.