Pharmacology of the Prostate in Non-Infectious Diseases

Prostate smooth muscle contraction and prostate growth are central topics in pharmacology of benign prostatic diseases. Both may drive urethral obstruction in benign prostatic hyperplasia (BPH), resulting in impairments of voiding and bladder emptying, and finally lower urinary tract symptoms (LUTS). Available drugs for medical treatment include α1-adrenoceptor antagonists and the phosphodiesterase-5 inhibitor tadalafil, improving symptoms and urinary flow by relaxation of prostate smooth muscle, and 5α-reductase inhibitors reducing the risk for progression, complications and surgery by inhibition of androgen-dependent growth. However, improvements by available medications are limited, so that surgery due to BPH is still inevitable in numerous patients. Ongoing experimental and clinical research aims to identify alternatives, and to understand current limitations of medical therapy. Non-adrenergic contractions of prostate smooth muscle recently moved into the focus of preclinical research, as they induce prostate smooth muscle contraction in parallel to α1-adrenoceptors. At molecular level, connections between regulation of prostate smooth tone and growth become increasingly obvious. This article summarizes principles underlying regulation of prostate smooth muscle contraction and prostate growth, available medications and clinical aspects, and recent attempts to identify novel targets and compounds for inhibition of smooth muscle contraction and proliferation in the prostate.