Prostatic α1-adrenoceptors: new concepts of function, regulation, and intracellular signaling.

Prostatic α1 -adrenoceptors are known to be involved in the pathophysiology of lower urinary tract symptoms (LUTS) in patients with benign prostate obstruction (BPO). It is widely accepted that enhanced α1 -adrenergic smooth muscle contraction can contribute to bladder outlet obstruction; α1 -adrenoceptor antagonists still represent a gold standard in the treatment of LUTS. Accordingly, expression and function of α1 -adrenoceptors in the prostate have attracted large attention over the last three decades. However, recent preclinical studies have challenged our understanding of prostatic α1 -adrenoceptors. In the current review article, we summarize "modern" concepts of prostatic α1 -adrenoceptors which include novel intracellular mediators of contraction as well as non-contractile signaling and post-translational receptor regulation. Configuration of α1 -adrenoceptors with binding partners may determine its function, leading to a dynamic receptor with high functional plasticity. Cooperative regulation of different intracellular effectors (MAPK, Akt, transcription factors) by α1 -adrenoceptors, hormones or growth factors has been suggested. The prostatic α1 -adrenoceptor is no longer being regarded as an isolated, static receptor exclusively mediating prostatic smooth muscle contraction by G proteins, but a dynamic receptor interacting with other receptors within a complex network of mediators.