KINETICS OF INCORPORATION OF N-3 TRANS FATTY-ACID IN RAT RETINA

Geometrical isomers of essential fatty acids are formed during heat tr eatment of vegetable oils. They are subsequently present in human diet . They have been reported to be elongated, desaturated and incorporate d in many rat tissues. The aim of the present study was to consider th e incorporation of trans (n-3) fatty acids in the rat retina, which is a docosahexaenoic acid (DHA)-rich tissue and often described as a pro tected structure against xenobiotics. Rats were fed for up to 8 weeks with a heated linseed oil, which is rich in geometrical isomers ct lin olenic acid. Isomers of linolenic acid, but also of eicosapentaenoic a cid (EPA) and DHA were found in the retina. The incorporation of the l atter is time-dependent, whereas the Delta 17 trans isomer of EPA incr eased strongly after 8 weeks of diet while it remained almost constant until 8 weeks. The percentage of incorporation of the trans isomer of DHA is almost the same than in the liver after 8 weeks of diet. It su ggests that the retina may not be much more protected than the liver a gainst long chain trans fatty acid incorporation.