Abstract
1. Ouabain was injected into the left renal artery of pentobarbitalized dogs and renal functions were measured by using clearance technics on separate kidneys.
2. Ouabain produced no increase but some decrease in GFR and ERPF in most instances, which is probably brought about by a vasoconstrictive action of ouabain.
3. In contrast to the inconsistent changes in GFR and ERPF, rates of urine flow and excretions of sodium and chloride were markedly increased in all instances.
4. There was no significant change in urinary potassium excretion.
5. The tubular reabsorption of sodium, chloride and water was consistently decreased.
6. Osmolar clearance was markedly increased in contrast to insignificant change in free-water clearance.
7. Meralluride injection showed similar changes in natruresis and diuresis and in reabsorption of water, sodium and chloride to ouabain.
8. These evidences lead to the conclusions that ouabain inhibits sodium transport in tubules.
