Metabolism of 3-(2', 4', 5'-triethoxybenzoyl) propionic acid, a new biliary smooth muscle relaxant with choleretic activity. II. Metabolism after repeated dosing in rats, in relation to choleretic activity.

1. Accumulation and possible induction in the metabolism of triethoxybenzoylpropionate were studied in rats in relation to the choleretic effect of the drug. Daily oral administration of [14 C] triethoxybenzoylpropionate showed no accumulation of drug or metabolites. Pre-treatment of rats with the drug did not induce its own metabolism or the metabolism of aminopyrine, p-nitroanisole, hexobarbital or zoxazolamine. 2. Choleresis in rats induced by triethoxybenzoylpropionate resulted from enhanced formation of the bile acid-independent fraction of canalicular origin, presumably mediated by the increased transfer of sodium into the canaliculi. This was not altered by repeated pre-treatment with the drug, in accordance with the metabolic findings.