Effects of dietary trans n-3 polyunsaturated fatty acids on the rat electroretinogram

Trans isomers of a linolenic acid are formed during heat treatment of vegetable oils. As a consequence, they are present in the human diet. Their effects on biological functions are not yet fully understood. In the present work, the effects of dietary trans n-3 fatty acids on the rat electroretinogram (ERG) were studied, as the retina is a tissue particularly rich in n-3 fatty acids. An isolated perfused rat retina model was used in order to monitor the b-wave of the ERG. A diet containing ethyl esters of trans alpha linolenic acid isomers or not (control) was given to Wistar male rats for 6 weeks. The incorporation of C22:6 Delta 19 trans fatty acid was studied after this feeding period. Dietary trans isomers of n-3 fatty acids significantly altered the maximal b-wave amplitude of the isolated retina. The low trans isomers incorporation in the total retina lipids suggests that further studies are needed to clarify how dietary trans n-3 fatty acids may act. (C) 1998 Elsevier Science Inc.