ABSTRACT
The effects of high erucic acid rapeseed oil (HER) on fatty acid oxidation in rat livers compared with low erucic acid rapeseed oil (LER) were studied. Weanling male SD rats were fed on 20% (% by weight, similarly hereinbelow) HER or LER diet for a week or 4 weeks, or 5% HER diet for 4 weeks. The hepatic capacity for oxidation of butyric acid and palmitic acid was determined by titrating the acetone produced by the fatty acid oxidation. The results showed that feeding HER to rats led to an increse in weight of liver and the extent of this increase was positively correlated to the intake of erucic acid (C22:1, n-9 cis). Feeding HER reduced the hepatic oxidation capacity for palmitic acid, notably in 20% HER (1 wk) group. Feeding LER had not shown this effect,indicating that erucic acid plays an important role in the toxicity of rapeseed oil. In the present study it was not found that the hepatic oxidation capacity for butyric acid was influenced by the intake of HER. Therefore, we considered that the inhibitory effect of HER on oxidation of long-chain fatty acids probably resulted from that the incorporation of erucic acid into mitocho-ndrial membranes interfered with the fatty acyl-CoA transfering system on the membranes, leading the fatty acyl-CoA to be unable to enter the mitochondria and to be oxidized there, but not from that the B-oxidation system in mitochondria was directly inhibited.