Dietary induced alterations in swelling characteristics and endogenous phospholipase A(2) activity of rat liver mitochondria.

The present study describes the rapid alterations in the fatty acid patterns of phosphatidyl choline and phosphatidyl ethanolamine from rat liver mitochondria induced by corn oil feeding to EFA-deficient rats. Simultaneous changes occurring with comparable rates were observed in the swelling properties and phospholipase A(2) activity of the mitochondria. Mitochondria isolated from the liver of EFA-deficient rats exhibited a high tendency to swell and a high phospholipase A(2) activity in comparison with those prepared from normal rat liver. Feeding of corn oil for 48 hr to the EFA-deficient rats completely reduced this high rate of swelling and phospholipase A(2) activity to the normal level. In the same time eicosatrienoic acid, a characteristic fatty acid constituent of phospholipids from EFA-deficient animals, was replaced by the more common fatty acids, linoleic and arachidonic. The possible relationship between fatty acid constituents of phospholipids, swelling properties and phospholipase A(2) activity in rat liver mitochondria are discussed.