Acta Pharmacologica Sinica 2008 February; 29 (2): 226-230; doi: 10.1111/j.1745-7254.2008.00728.x

Aim: The aim of the present study was to investigate the effect of androgen and estrogen on mitosis orientation in the prostate epithelial cells of male rats.

Methods: Castrated rats were treated with a single injection of testosterone propionate (TP) or benzogynestry (E₂). There were 8 rats in the control group and TP-treated or E₂-treated group. Prostate, liver, a specimen of skin, and a segment of the jejunum and colon were removed after the corresponding treatment. The results were observed through immunohistochemistry and iron hematoxylin-eosin staining.

Results: All mitoses found in the prostate epithelial cells of castrated rats with TP were oriented parallel to the basement membrane; however, mitoses found in the prostate epithelial cells of castrated rats in E₂ and the control group were oriented perpendicular to the basement membrane. TP treatment resulted in marked changes in mitosis orientation in the prostate epithelial cells. Bromodeoxyuridine-labeled positive cells could be seen throughout the stroma and prostate epithelial cells with an injection of TP; however, the positive cells could only be seen in the stroma of prostate with an injection of E₂, and the positive cells could hardly be seen in the control group.

Conclusion: We found a novel effect of TP in the prostate as a marked change of mitosis orientation in prostate epithelial cells.

Keywords: prostate; mitosis orientation; testosterone propionate; benzogynestry; estrogen; proliferation