EVALUATION OF SOME 1- AND 7-SUBSTITUTED METHYLATED XANTHINES AS DIURETICS IN THE RAT

¹ Dept. of Pharmacology, University of Toronto, Toronto, Canada

A series of 1-and 7-substituted xanthines have been tested as diuretics in the male rat.

In "non-primed" rats, theophylline, aminophylline, 7--methoxy--hydroxy propyl-,7-isoamyl-, 7-hydroxyethyl- and 7-allyl-theophylline were the only derivatives of this series to produce a significant increase in urine output over controls.

In rats "primed" with 0.45 per cent saline, 7-chloroethyl-theophylline, theophylline, aminophylline, caffeine sodium benzoate, theobromine sodium acetate, 1-allyl-theobromine, 7---dihydroxypropyl-theophylline produced significant diuretic responses. 7-Chloroethyl-theophylline was the most effective diuretic in the "primed" rat.

A comparison of caffeine, theophylline and theobromine in the "primed" male rat demonstrated that theophylline was the most potent diuretic. Little difference was observed between the response of caffeine and theobromine under these conditions.