Effects of estradiol on prostate hypeplasia in castrated rats

AIM To investigate whether 50 μg·kg~ -1 estradiol can inhibit the proliferation of hyperplastic prostate induced by testosterone propionate(TP). METHODS ① 60 male Sprague-Dawley(SD) rats divided into five groups at random. One as normal control group, the other groups were negative control group, TP control group, estradiol group and finasteride group. Except the normal control group, the rats of other groups were castrated. One week after castration, the rats of TP control group were treated with 0.5 mg·d~ -1 TP, the estradiol group was treated with 0.5 mg·d~ -1 TP and 50 μg·kg~ -1 estradiol, the animal of finasteride group were treated with 0.5 mg·d~ -1 TP and 10 mg·kg~ -1 finasteride for 31 d. ② 30 male SD rats divided into five groups and were castrated, one week later, four groups were treated with 50, 100, 200 or 400 μg·kg~ -1 estradiol respectively for 14 d, meanwhile, all animal were treated with 0.5 mg·d~ -1 TP. Animals were anesthetized to death, the prostate was dissected and their weights were measured and their prostate index(PI) was calculated. The height of epithelial cell and acinar luminal area were measured with micro image analysis software. RESULTS ① After being treated with 50 μg·kg~ -1 estradiol for 31 d, between TP control group and estradiol group, there were no differences in these indexes, including the mean prostate volume, mean prostate wet weight, prostate index, mean height of epithelial cell and mean gland lumen area of prostate. While in finasteride group, the values of all indexes were smaller than that of TP group (P0.01). ② In 400 μg·kg~ -1 group, the mean prostate wet weight was increased, the mean PI increased, the mean height of epithelial cell and the mean gland lumen area of prostate were signicantly increased as compared with that of control group(P0.01). CONCLUSION 50 μg·kg~ -1 and more estradiol can not inhibit the proliferation of hyperplasia prostate that induced by TP, on the contrary, they promote the prostate to proliferate.