Abstract
Effects of ethacrynic acid on mitochondrial Ca2+-accumulation were examined in the rat kidney. The inhibitory effect of the drug on Ca2+-accumulation was reversed by cysteine or gluthathione. The addition of phosphate to the medium abolished the inhibitory effect of ethacrvnic acid on Ca2+-accumulation of kidney cortex mitochondria. On the other hand, acetate enhanced that of the drug. The inhibition of Ca2+-accumulation by mersalyl was reversed by cysteine, but was not by phosphate, differing from ethacrynic acid. Ethacrynic acid inhibited the activity of mitochondrial ATPase observed in the presence of CaCl2, but not the enzyme activity in the presence of MgCl2. The main inhibitory effect of ethacrynic acid on mitochondrial Cat2+-accumulation may be due to an action on mitochondrial ATPase.
