alpha1- and alpha2-adrenoceptors in BPH.
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.
Takeda
M
M
Department of Urology, Niigata University School of Medicine, Niigara, Japan. takedama@med.niigata-u.ac.jp
Hatano
A
A
Arai
K
K
Obara
K
K
Tsutsui
T
T
Takahashi
K
K
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use; D006801:Humans; D008297:Male; D011470:Prostatic Hyperplasia / Q000188:drug therapy / Q000503:physiopathology*; D018340:Receptors, Adrenergic, alpha-1 / Q000145:classification / Q000502:physiology*; D018341:Receptors, Adrenergic, alpha-2 / Q000502:physiology*
D000317:Adrenergic alpha-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D018341:Receptors, Adrenergic, alpha-2