[Effect of diuretics on electrolyte and non-electrolyte penetration of intercellular spaces]

The effect of novurit, mannitol and furosemide on permeability of the intercellular interstice of the frog urinary bladder by inulin, saccharose, iodide, lithium cation and fluorescein moving against a concentration gradient was examined. Novurit (0.5--6 mM/l) raised permeability of the intercellular interstice by all test substances and ions. Mannitol (210 mM/l) increased permeability of the intercellular interstice by lithium cation and fluorescein, while furosemide failed to exert any effect on permeability. The character of asymmetrical ionic flows moving in opposite directions across the wall of the frog urinary bladder is discussed.