Testosterone induces vascular endothelial growth factor synthesis in the ventral prostate in castrated rats

Purpose: Recent studies suggest that the vasculature is important for the c ontrol of prostate growth. Castration induces an involution of the prostate gland and its vasculature. Replacement of testosterone stimulates endothel ial cell proliferation and normalizes vascular volumes and blood flow sever al days before organ regrowth. Antiangiogenesis treatment inhibits the grow th of prostate tumors. Understanding the regulation of the prostate vascula ture may therefore provide important knowledge of the mechanisms responsibl e for the growth of non-malignant and malignant prostate tissue. Castration induced regression and testosterone stimulated regrowth of the prostatic v asculature have here been used to study the involvement of the angiogenic f actor vascular endothelial growth factor (VEGF) and its receptors flt-1 and flk-1/KDR in the regulation of the prostatic vasculature. Materials and Methods: VEGF, flt-1, and flk-1/KDR levels were quantified in the rat ventral prostate following castration and testosterone replacement . Methods used were competitive RT-PCR, Western blot and immunohistochemist ry. Results: VEGF mRNA and protein levels were significantly decreased by castr ation and testosterone treatment induced VEGF synthesis in the rat ventral prostate epithelium. Flt-1 and flk-1/KDR receptor levels were unaffected by castration and testosterone treatment. Conclusions: Castration down regulates VEGF and testosterone induces VEGF s ynthesis in epithelial cells in the rat ventral prostate.