Prostatic ischemia induces ventral prostatic hyperplasia in the SHR; possible mechanism of development of BPH.

In the light of increasing evidence that benign prostatic hyperplasia is associated with cardiovascular disease, we have investigated the relationship between prostatic blood flow and prostatic hyperplasia in the spontaneously-hypertensive-rat (SHR). Twelve-week-old male SHRs were treated with nicorandil for six weeks. Wistar-Kyoto rats were used as controls. Six weeks after nicorandil treatment, blood pressure and the prostatic blood flow were estimated, and tissue levels of malondialdehyde, HIF-1α, TGF-β1, bFGF, dihydrotestosterone, and α-SMA were measured. SHRs showed significant increases in blood pressure, tissue levels of malondialdehyde, HIF-1α, TGF-β1, bFGF, α-SMA and a significant decrease in the prostatic blood flow. Although treatment with nicorandil failed to alter the blood-pressure and α-SMA, it significantly ameliorated the increased levels of malondialdehyde, HIF-1α, TGF-β1, and bFGF. There were no significant differences in tissue levels of dihydrotestosterone among any groups. These data indicate that development of prostatic hyperplasia may be associated with prostatic hypoxia, which nicorandil prevents via its effect to increase the blood flow.