Decrement of blood flow precedes the involution of the ventral prostate in the rat after castration

Abstract

Blood flow to the rat ventral prostate (VP), dorsolateral prostate (DP), and Dunning R3327 prostatic tumors was measured at different times up to 7 days after castration, using the microsphere method. In the VP organ weight was decreased from day 3 onwards. Blood flow was, however, already significantly decreased from day 1. The reduced blood flow in VP in 1-3 and 7-day castrated animals could be reversed by testosterone treatment. Organ weight was slightly decreased but blood flow was unaffected by castration in DP. Castration left Dunning tumor volume and blood flow unaffected. Using immunohistochemistry, androgen receptors were observed in epithelial and stromal cells in VP, DP and Dunning tumors, but not in blood vessels. Castration is known to induce apoptosis in the VP, but not in the DP or in Dunning tumors. This suggests that a reduction in blood flow might be an important component for the castration-induced involution and apoptosis in prostatic tissue. The reason why castration reduces blood flow only in the VP, and not in the DP or Dunning tumor is unknown.

Effect of short-term finasteride therapy on peroperative bleeding in patients who were candidates for transurethral resection of the prostate (TUR-P): a randomized controlled study

“…4 Furthermore, as outlined in the Introduction, animal and human studies with finasteride established a reduction in prostatic blood flow and vascular density. 9,10 It is well known that finasteride reduces size of the prostate gland, and this process may take up to 6 months.…”

“…1 Blood loss is one of the most important causes of morbidity during TUR-P. 2 It has been previously demonstrated that androgen deprivation induces a marked involution of the vasculature in rat prostate and testosterone treatment rapidly reverses this process. [3][4][5] The effect of finasteride, which is a 5-alpha-reductase inhibitor, on prostatic bleeding due to BPH is well documented. It also decreases the incidence of surgery and acute retention besides limiting hematuria in patients with BPH.…”

DCE and DW MRI in monitoring response to androgen deprivation therapy in patients with prostate cancer: A feasibility study

“…DCE MRI has been validated as a surrogate marker of tumor angiogenesis in prostate cancer and other primary tumors (21,22). In murine models, androgen ablation has been shown to suppress the production of the angiogenic factor VEGF (vascular endothelial growth factor) by the glandular epithelium and induce apoptosis of endothelial cells (23,24). Thus, there is good evidence for the antiangiogenic role that androgen ablation plays in the prostate.…”

Physiological apoptosis in hormone-dependent tissues: involvement of caspases

“…57 Changes in the level of blood flow resulting in local hypoxia may also initiate epithelial cell apoptosis in the ventral prostate. 58,59 Following castration, blood flow in the prostate rapidly decreases, most likely due to endothelial cell apoptosis. 59 The resulting hypoxic conditions might be responsible for causing epithelial cell death.…”