COMPARATIVE-STUDIES ON BETA-ADRENOLYTIC POTENCIES OF SOME NEW PHENOXYAMINOPROPANOL DERIVATIVES AND CELIPROLOL

The influence of different substitutions in 4-position of the phenyl r ing of three recently developed 1-alkylamino-3-phenoxy-2-propanol deri vatives on the beta-adrenolytic potency and tissue specificity has bee n investigated and compared to the cardioselective beta-adrenoceptor a ntagonist celiprolol. The pA(2) values against the isoprenaline tachyc ardia in isolated right atria (beta(1)) and the relaxation of tracheal muscle (beta(2)) both of guinea-pigs were expressed as beta(1)/beta(2 ) selectivity ratio. The efficiencies and cardioselectivity of 4-propo xycarbonylderivative (BL 345 Ac) as well as celiprolol were similar, w hereas 4-propoxymetylsubstitution (FoA 34t) decreased the inhibiting p otency to the heart tissue nearly three times. The elimination of the 4-substitutent leads to the total loss of cardioselectivity (FoA 04), In addition, the character of the 4-substition has also influenced the nonspecific membrane activity expressed as local anesthetic efficienc y in experiments on rabbit eyes and guinea-pig skin.