Renal clearance procedure for the rat: effect of dopamine and standard saluretics

Four standard diuretic compounds were evaluated for electrolyte output, effects on glomerular filtration rate (GFR), and effective renal plasma flow (RPF) in an anaesthetized rat preparation. Triamterene, hydrochlorothiazide, acetazoleamide and furosemide exerted their characteristic diuretic effects at doses which did not significantly change GFR or RPF. Regulation of the rate of a 3% mannitol-0.9% NaCl infusion to rats permitted the establishment of GFR and RPF values which were approximately in the middle of the reported range for this species. A significant increase in RPF without a concurrent rise in GFR was produced with dopamine. This was effectively blocked by the peripheral dopamine inhibitor, bulbocapnine.