Age-related change of the role of alpha1L-adrenoceptor in canine urethral smooth muscle.
To examine age-related alteration of the role of alpha1L-adrenoceptor in the urethra, young non-parous and aged parous female dogs were used. In a functional study, we evaluated phenylephrine-induced contraction and antagonistic effects of JTH-601, a newly synthesized alpha1-adrenoceptor antagonist, and prazosin; in a localization survey using autoradiographic technique, we investigated specific [3H]JTH-601 and [3H]tamsulosin binding. Concentration-response curves were obtained for phenylephrine (pD2 = 5.0-5.3). JTH-601 and prazosin antagonized this contraction with pA2 values of 8.2-8.3 and 8.0-8.1, respectively. Specific binding of both [3H]JTH-601 and [3H]tamsulosin were observed in the bladder neck and proximal section of urethra. There were no significant differences of the pD2, pA2, and radio ligand binding between young non-parous and aged parous dogs.
Suzuki
Y
Y
Central Pharmacological Research Institute, Japan Tobacco, Inc., Osaka.
Moriyama
N
N
Okaya
Y
Y
Nishimatsu
H
H
Kawabe
K
K
Aisaka
K
K
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000378:metabolism / Q000494:pharmacology; D000375:Aging / Q000502:physiology*; D000818:Animals; D001345:Autoradiography; D001667:Binding, Competitive / Q000187:drug effects; D003408:Cresols / Q000378:metabolism / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D010298:Parity; D010646:Phentolamine / Q000378:metabolism / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000502:physiology*; D013449:Sulfonamides / Q000378:metabolism / Q000494:pharmacology; D000077409:Tamsulosin; D014521:Urethra / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D003408:Cresols; D018340:Receptors, Adrenergic, alpha-1; D013449:Sulfonamides; D014662:Vasoconstrictor Agents; D010656:Phenylephrine; C101291:JTH 601; D000077409:Tamsulosin; D011224:Prazosin; D010646:Phentolamine