[The role of alpha1-adrenoceptor subtypes in benign prostatic hyperplasia-from bed to bench]

Alpha 1-adrenoceptors (alpha1-ARs) play a role in the regulation of prostatic smooth muscle tone, and are critical mediators of lower urinary tract symptoms (LUTS) and pathophysiology in benign prostatic hyperplasia (BPH). Three subtypes (alpha1a, alpha1b, alpha1d) have been identified by molecular cloning techniques. Although the reasons for the existence of three subtypes remain elusive, recent findings suggest a role of subtype and tissue-specific regulation. We examined the role of each alpha1-AR-subtype in the prostate to apply some new findings obtained from basic research for the clinical treatment. We have demonstrated that the mRNA expression levels of alpha1-AR-subtypes in the prostate differed among patients and that the genetic background differences of patients with BPH were responsible for the diverse responses to subtype-selective alpha1-blockers. In addition, both alpha1a- and alpha1d-AR-subtypes play a significant role in the spontaneous contraction of human prostate and, especially alpha1d-AR-subtypes may also control the cell growth of the prostate. Clarification of the mechanism of alpha1-AR subtypes in the prostate will provide more effective therapy for BPH patients.