Dietary fatty acid composition differently influences retinoylation reaction in rat testes mitochondria

All-trans-retinoic acid (atRA) is incorporated covalentlyinto proteins of rat testesmitochondria. In this study,the effect of three diets with different fatty acid compositionon the retinoylation of proteins of rat testes mitochondria hasbeen investigated. Different groups of rats were fed on a basaldiet supplemented with 15% of either coconut oil (CO), oliveoil (OO) or fish oil (FO).We found that,when compared withCO, the binding of retinoic acid was decreased in FO- andOO-fed rats. Mitochondrial phospholipids composition wasdifferently influenced by dietary treatments; minor changeswere observed in fatty acid composition of phospholipids.Few differences were observed in the Arrhenius plots amongthe three groups of rats. Kinetic analysis revealed a decreasein the Vmax value in FO- and OO- as compared with CO-fedrats. No difference among the three groups were observedin the KM value. The retinoylation reaction was inhibited by13-cis-RA and 9-cis-RA.