Further Evidence that (±)-Carteolol-induced Relaxation is Mediated by β_2-Adrenoceptors but not by β_3-Adrenoceptors in the Guinea Pig Taenia Caecum

概要

論文の詳細を見る
The properties of the β_1- and β_2-adrenoceptor partial agonist (±)-carteolol were investigated against the β_2- and β_3-adrenoceptors of the taenia caecum of the guinea pig. (-)-Isoprenaline and (±)-carteolol induced concentration-dependent relaxation in this tissue. The non-selective β_1- and β_2-adrenoceptor antagonist (±)-propranolol (10-100 nM), the selective β_2-adrenoceptor antagonist ICI 118, 551(10-100 nM)and the non-selective β_1-, β_2-and β_3-adrenoceptor antagonist (±)-bupranolol (10-100 nM), caused a concentration-dependent rightward shift of the concentration-response curves for (-)-isoprenaline and (±)-carteolol. Schild regression plot analyses carried out for (±)-propranolol against (-)-isoprenaline and (±)-carteolol gave pA_2 values of 8.35 and 8.24, respectively. Schild plot analyses of ICI 118, 551 against (-)-isoprenaline and (±)-carteolol gave pA_2 values of 8.47 and 8.41, respectively. Schild plot analyses of (±)-bupranolol against (-)-isoprenaline and (±)-carteolol gave pA_2 values of 8.47 and 8.53, respectively. Slopes of the Schild plots were not significantly different from unity. These results suggest that the relaxant effects of (±)-carteolol in the guinea pig taenia caecum are mediated by β_2-adrenoceptors but not by β_3-adrenoceptors.
日本平滑筋学会の論文