[Propentofylline and its analogs: a new class of agents for in vitro study of the antidiuretic response].

We took profit in this work of the discovery of a novel series of trialkylxanthines, with a biological activity greater than that of the other methylxanthines classically used as cAMP phosphodiesterase inhibitors. First, we determined their hydrosmotic activity, with the hope to find out compounds that could be used as apical agonists. Second, we employed these compounds as tools to further analyze the cellular mechanism of hydrosmotic response. Results show that propentofylline, the most potent compound in this series, exhibits a comparable activity whatever the side of administration, apical or basal. Results further show a similar mode of action in most of the studied conditions. They suggest thus that the same mechanism of action, probably an inhibition of cAMP phosphodiesterase is involved in both apical and basal stimulation. However, they reveal the existence of characteristics that are specific to the apical response. This suggest that an additional mechanism of action is possibly involved in the apically-induced hydrosmotic response.