Inhibition by indomethacin of the renal response to an acute saline load in the dog.

The kidneys of sodium-loaded dogs, treated by indomethacin before their transplantation to the neck vessels of sodium-depleted animals, lose their ability to increase the fractional excretion of sodium following an intravenous infusion of saline; they behave similarly to the kidneys of sodium-depleted dogs. Moreover, they become unable to potentiate the response of the kidneys of the sodium-depleted perfusors. The experimental conditions exclude a direct effect of the drug eo ipso. The results indicate that renal prostaglandins are involved in the adjustment of the renal response to saline loading, depending on the previous dietary sodium balance, and that they are related with the potentiating factors released into the blood by the kidneys of sodium-loaded animals.