The unsaturated fatty acid content of mitochondria in relation to oxidation of exogenous reduced nicotinamide adenine dinucleotide

Abstract

Liver mitochondria isolated from essential fatty acid-deficient rats oxidize in hypotonic solution exogenous NADH more slowly than mitochondria isolated from normal rats. Because this difference becomes apparent with the onset of the essential fatty acid deficiency, and disappears when the deficient animal is fed a normal (essential fatty acid-sufficient) diet it appeared that measurement of NADH oxidation rates might be the basis of an in vitro assay for essential fatty acid deficiency. However, no close correlation between the pattern of mitochondrial fatty acid unsaturation and the ability to oxidize NADH could be observed. Indeed, diets could be manipulated in several ways to produce conditions wherein mitochondria presumably sufficient in essential fatty acids exhibited either a low capacity to oxidize NADH, similar to essential fatty acid-deficient mitochondria, or the reverse. It is concluded that the pattern of mitochondrial fatty acid unsaturation may vary widely without affecting the capacity to oxidize NADH, and presumably, therefore, the specific stability of the membrane.