Distribution of alpha1L-adrenoceptors in canine prostate: characterization by quantitative autoradiography.
Our aim was to determine the distribution of alpha1L-adrenoceptors in canine prostate by an autoradiographic technique using [3H]JTH-601 (an alpha1L-adrenoceptor antagonist) and [3H]JTH-601-G1 (an active metabolite of JTH-601). Prostates were removed from three male beagle dogs. Several slices of the specimens were incubated with 5 nM of [3H]JTH-601, [3H]JTH-601-G1 and [3H]tamsulosin (an alpha1A-adrenoceptor antagonist). For macroscopic autoradiography, visualization was performed using an imaging plate and image-analyser. To examine microscopic localization of binding sites, preparations were exposed, developed and fixed. Specific binding of [3H]JTH-601 and [3H]JTH-601-G1 was observed diffusely throughout the entire interstitium on macroscopic autoradiography. Specific binding of [3H]tamsulosin was also recognized although the binding was weaker than that of [3H]JTH-601. On microscopic autoradiograms, the grains of each ligand were mainly distributed on smooth muscle. These results indicate morphologically that specific binding sites of JTH-601 and JTH-601-G1 exist in canine prostate, suggesting the distribution of alpha1L-adrenoceptors in this tissue, in addition to alpha1A-adrenoceptors.
Suzuki
Y
Y
Central Pharmaceutical Research Institute, Japan Tobacco Inc., Takatsuki, Osaka.
Moriyama
N
N
Okaya
Y
Y
Kanada
A
A
Nishimatsu
H
H
Kawabe
K
K
Aisaka
K
K
D000317:Adrenergic alpha-Antagonists; D000818:Animals; D001345:Autoradiography; D003408:Cresols; D004285:Dogs; D008297:Male; D011467:Prostate / Q000502:physiology*; D018340:Receptors, Adrenergic, alpha-1 / Q000032:analysis*
D000317:Adrenergic alpha-Antagonists; D003408:Cresols; D018340:Receptors, Adrenergic, alpha-1; C101291:JTH 601