Ethanol exposure causes a decrease in docosahexaenoic acid and an increase in docosapentaenoic acid in feline brains and retinas.

Alcohol altered the fatty acyl composition of the liver, brain, and retina of domestic felines that were maintained on a diet having low, but adequate, amounts of essential fatty acids. For 8 mo, seven adult cats were provided a diet with 10% fat (by wt), consisting of 9:1 ratio of hydrogenated coconut oil:corn oil. During 6 of these 8 mo, four of the cats were given oral daily doses of a 95% ethanol solution (1.2 g.kg-1.d-1). Cats were killed and the fatty acyl composition of tissues were determined. In the plasma and livers of the alcohol-exposed animals, there were significant decreases in the concentrations of 18:2 omega 6, 20:4 omega 6, 22:5 omega 3, and 22:6 omega 3 and increases in the concentrations of the nonessential fatty acids 16:1 omega 7, 18:1 omega 9, and 20:3 omega 9. In the brains and retinas of the alcohol-exposed animals, 22:6 omega 3 decreased by 17% and there was a compensatory increase in 22:5 omega 6. In the retinas, the concentration of 22:5 omega 6 increased by 250%. The reciprocal change in the ratio of 22:6 omega 3 to 22:5 omega 6 is known to be associated with a loss in nervous system function and may provide a biochemical mechanism underlying some of the neuropathology associated with alcoholism.