Micropuncture study of the effect of various diuretics on sodium reabsorption by the proximal tubules of the dog.

The precise sites of action of various diuretics within the nephron have been the subject of numerous investigations and considerable debate for several decades. Inhibition of sodium transport in the proximal tubule has, at one time or another, been considered to play a major role in the action of virtually every group of diuretics. However, such actions on the proximal tubules have been inferred only from indirect evidence. The technique of micropuncture allows a more direct evaluation of the effects of pharmacologic agents on sodium reabsorption by the proximal tubules.