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Updated: Aug 17, 2026

Bladder Smooth Muscle Strip Contractility as a Method to Evaluate Lower Urinary Tract Pharmacology
Published on: August 18, 2014
alpha1- and alpha2-adrenoceptors in BPH
1Department of Urology, Niigata University School of Medicine, Niigara, Japan. takedama@med.niigata-u.ac.jp
Abstract:
The dynamic obstruction of the bladder outlet secondary to benign prostatic hyperplasia (BPH), and the contractile properties of the human prostate are mediated primarily by alpha1-adrenoceptors. There are now at least three subtypes (A, B, and D) of alpha1-adrenoceptors, and recent work revealed that alpha1A-adrenoceptor and alpha1B-adrenoceptor may have a prime role for prostatic obstruction, and contraction of artery, respectively. Very recently, the presence of a low affinity alpha1-adrenoceptor for prazosin, named alpha1L, in the human BPH tissue has been determined. Because the DNA sequence of alpha1L-adrenoceptor has not yet been cloned, the alpha1L-adrenoceptor may be another form of the alpha1A-adrenoceptor, or another pharmacologically distinct alpha1-adrenoceptor which mediates the norepinephrine-induced contraction of the prostatic smooth muscle. Furthermore, the contribution of alpha1-adrenoceptors in the prostate to symptoms (not only obstructive, but irritative symptoms) which are elicited by prostatic obstruction remains to be determined.
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