Abstract: | Ethacrynic acid administered to anesthetized dogs was found to increase the level of prostaglandin E as determined by radioimmunoassay in renal venous blood at the time when renal blood flow was increased by this agent. No change was found in the renal venous level of prostaglandin F. When ethacrynic acid was administered after treatment with indomethacin, which blocks the increase in renal blood flow induced by the natriuretic agent, no increase in the renal venous level of prostaglandin E was seen. Thus, the dilation of the renal vasculature would appear to be caused by a stimulation of synthesis and release of prostaglandin E by ethacrynic acid. |