Uterine relaxant effects of mono- and dibenzyloxyindanpropionic acids

DIPA [5,6-bis(dibenzyloxy)-1-oxo-2-propyl-2-indanpropionic acid] and MIPA (5-benzyloxy-1-oxo-2-butyl-2-indanpropionic acid) were evaluated for relaxant effects on the estrogenized isolated rat uterus. In a concentration-dependent and reversible manner DIPA (10(-5)-3x10(-4)M) inhibited uterine contractions induced by PGF2 alpha, KCl and BaCl2, and MIPA (10(-5)-3x10(-4)M) inhibited the oxytocic effects of PGF2 alpha, PGE2, acetylcholine and BaCl2. Further evaluation of DIPA demonstrated its selectivity for uterine smooth muscle since it did not interfere with carbachol-induced increased tone nor isoproterenol-induced decreased tone of the isolated guinea pig trachea, nor did it inhibit the positive inotropic effects of isoproterenol on the isolated guinea pig atrium.