Effect of JTH-601, a putative alpha(1L)-adrenoceptor antagonist, on guinea pig nasal mucosa vasculature.
The existence of alpha(1)-adrenoceptors with low affinity for prazosin, an alpha(1L) subtype, has been proposed in addition to alpha(1)-adrenoceptor subtypes with high affinity for prazosin, i.e. the alpha(1H) group: alpha(1A), alpha(1B) and alpha(1D) subtypes. In the present study, we investigated the effect of JTH-601 (3-(N-[2-(4-hydroxy-2-isopropyl-5-methylphenoxy)ethyl]-N-methylaminomethyl)-4-methoxy-2,5,6-trimethylphenol hemifumarate), a putative alpha(1L)-adrenoceptor antagonist, on the isolated guinea pig nasal mucosa vasculature. JTH-601 (0.01-0.03 microM) competitively antagonized the noradrenaline-induced contraction of the tissue in a concentration-dependent manner. The pA(2) value for JTH-601 was 8.14 +/- 0.04 (means +/- SEM, n = 6). The data suggests that the alpha(1L)-subtype is involved in the noradrenaline-induced contraction of the guinea pig nasal mucosa vasculature.
Department of Otorhinolaryngology, Hiroshima University School of Medicine, 1-2-3 Kasumi, Minami-ku, 734-8551, Hiroshima, Japan.
T
T
Hirai
H
H
Tsuru
N
N
Tanimitsu
K
K
Yajin
M
M
Sasa
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D003408:Cresols / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009297:Nasal Mucosa / Q000098:blood supply*; D009638:Norepinephrine / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D003408:Cresols; D014662:Vasoconstrictor Agents; C101291:JTH 601; D009638:Norepinephrine