Male lower urinary tract symptoms and α1D-adrenoceptors


Correspondence: Osamu Ishizuka M.D., Department of Urology, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan. Email:


Historically, α1-adrenoceptors have been classified into three subtypes (α1A, α1B and α1D) that are widely distributed in various organs. Research on the α1D-adrenoceptors in the bladder, urethra and prostate has focused on the relationship between expression levels and symptoms of bladder outlet obstruction, and the implications and functional roles of α1D-adrenoceptors subtypes in these organs. The α1D-adrenoceptor messenger ribonucleic acid and protein seem to be increased in obstructed bladders or small capacity bladders. In contrast, α1D-adrenoceptor subtype knock-out mice have been found to have a prolonged voiding interval. Interestingly, an α1D-adrenoceptor antagonist was found to inhibit the facilitation of afferent nerve activity for the micturition reflex induced by intravesical infusion of acetic acid. Clinically, patients who felt urgency at low filling volumes and had a small bladder capacity were found to have more α1D-adrenoceptor messenger ribonucleic acid in their bladder mucosa than patients who felt urgency at high filling volumes and had a large bladder capacity. An α1D-adrenoceptor antagonist was found to increase the first desired volume and the maximum desired volume while decreasing detrusor overactivity in pressure flow studies. Thus, α1D-adrenoceptors in the lower urinary tract might play an important role in the pathophysiology of lower urinary tract disorders.