TESTOSTERONE STIMULATES ANGIOGENESIS AND VASCULAR REGROWTH IN THE VENTRAL PROSTATE IN CASTRATED ADULT RATS

The castration-induced regression and testosterone stimulated regrowth of the vasculature in the rat ventral prostate lobe were studied usin g stereological techniques. Seven days after castration, the endotheli al cell proliferation rate (bromodeoxyuridine labeling index); the tot al weights of blood vessel walls, blood vessel lumina, endothelial cel ls, glandular epithelial cells; and total organ weight were all decrea sed. Within 2 days after sc treatment with testosterone, the total wei ghts of blood vessel walls, endothelial cells, and vascular lumina, as well as the endothelial cell proliferation rate, were all normalized. In contrast to the rapid response of the vasculature, the total weigh t of glandular epithelium and total organ weight were not normalized d uring the 4 days of testosterone treatment. Growth of the vasculature apparently precedes growth of the glandular epithelium. The testostero ne-dependent factors stimulating the vasculature are unknown, but fact ors derived from epithelial cells, mast cells (which accumulate in the prostate during the first day of testosterone treatment), and tissue macrophages could all be involved. Castration-induced regression and t estosterone-stimulated regrowth of the prostatic vasculature can be us ed as an experimental model to study factors regulating angiogenesis a nd organ growth in the prostate.