Attenuation by d-ozolinone of l-ozolinone-induced diuresis in rats

The effect of the non-diuretic dextrorotatory isomer of ozolinone on l- ozolinone -induced diuresis was studied in anesthetized rats. After intravenous application d- ozolinone attenuated l- ozolinone -induced increase in renal fluid, sodium, potassium and chloride excretion. Microperfusion experiments of the loop of Henle in vivo revealed that no interaction between the two stereoisomers occurred at this main site of tubular action of l- ozolinone . Since both isomers share the same organic acid transport pathway in the proximal tubule it is assumed that d- ozolinone attenuates the l- ozolinone -induced diuresis because it depresses proximal secretion of l- ozolinone and thereby partially prevents transfer of this diuretic to the tubular fluid.