Associations between androgen receptor and tyrosine phosphorylated protein expressions in rat prostate gland.

Abstract

Mammalian prostate gland plays a role in alkaline substance synthesis including proteins. These functions are depending on glandular maturation and testosterone-androgen receptor (AR) dependent actions. Since tyrosine phosphorylated (TyrPho) proteins, also important for secreting pathways, have been localized in the androgen dependent organs, association between AR and TyrPho protein expressions in prostate is still unknown. This study aimed to investigate the changes of such proteins in prostate gland of male castrated rats. Nine prepubertal and adult twenty-two adult male rats were divided into the prepubertal (Pre, n=9), Sham (n=6), castrate for 3 (Cas-3, n=8) and for 7 (Cas-7, n=8) days groups, respectively. Serum testosterone level was determined. Histology and AR localization in each prostatic lobe were observed. TyrPho and AR protein expressions were also examined. The results showed undetectable testosterone level and low AR expression in Pre and Cas prostates with the decreased size. Few histopathologies were found in Cas groups. In ventral lobe, a Tyrpho protein was increased at the 48 kDa but the 52, 33, and 26 kDas were decreased in the Pre and Cas groups. For dorsolateral lobe, they were decreased at 33 and 30 kDas in Pre group and only 30 kDa was decreased in Cas-3 group. In the anterior lobe, the TyrPho proteins 57, 49, 39, 30, and 26 kDas were decreased in Pre group while 57, 30, and 26 kDas were decreased in Cas-3 group. In conclusion, the alterations of testosterone level and AR expressions associate with TyrPho protein expressions in prostate gland during development.