AbstractDiuretic effects of seven orally-acting diuretic agents have been examined in the mouse. The following compounds, examples of various types of orally active compound available, produced their characteristic diuretic effects: bendrofluazide, frusemide, ethacrynic acid, acetazolamide, triamterene, aminophylline and Su 15049A. The diuretic effects of the various agents were demonstrated under both water and saline-loading conditions. After allowing for differences in baseline sodium excretion, all diuretics except acetazolamide caused a further enhancement of sodium excretion after saline-loading compared with water-loading tests. The mouse possesses several advantages over the more commonly used rat since the range of diuretic responsiveness is greater. These results suggest that the mouse is a suitable species for diuretic testing.