Excessive intake of 13-cis retinoic acid and fatty acid composition of tissues.

The effects of feeding an excess of 13-cis retinoic acid on the fatty acid composition of tissues were studied. Groups of male, weanling, Sprague-Dawley rats were fed diets containing 0, 100 and 300 mg 13-cis retinoic acid per kilogram diet. Rats were killed 4 weeks after feeding the diets, and the fatty acid composition of total lipids in plasma, liver, kidney, heart and lung was determined. Changes in fatty acid patterns were observed primarily in plasma and liver. The proportions of 16:1, 18:1 and 20:3 omega 6 were generally higher, whereas those of 20:4 were lower. The fatty acid composition of kidney, heart and lung lipids was not appreciably changed. The results on fatty acid changes in liver suggest that 13-cis retinoic acid may be modifying the activities of desaturating enzymes.