The relative amounts of long-chain acylcarnitines, short-chain acylcarnitines and carnitine in heart, liver and brown adipose tissue from rats fed on rapeseed oil

Abstract

1. The amount of long-chain acylcarnitines relative to the total carnitine (fractional amount) was determined in the heart, liver and intrascapular brown adipose tissue of rats fed on diets rich in rapeseed oil or corn oil, or a carbohydrate-rich stock diet, for 4 days or 4 weeks. The relative amounts of free carnitine and short-chain acylcarnitines were also determined in rats fed on the diets for 4 days. 2. No differences were found in the fractional amount of long-chain acylcarnitines of the heart between the rapeseed oil-and the corn oil-fed groups, neither after 4 days nor after 4 weeks on the fat diets. 3. In the liver and brown adipose tissue the fractional amount of long-chain acylcarnitines increased more than twice after 4 days on rapeseed oil as compared with corn oil. 4. The fractional amount of long-chain acylcarnitines in the liver and brown adipose tissue had decreased significantly after 4 weeks of rapeseed oil feeding. In the liver there were no differences between the two fat-fed groups at this stage. 5. No significant differences were found in the relative amounts of free carnitine and short-chain acylcarnitines between the corn oil- and the rapeseed oil-fed rats after a feeding period of 4 days. 6. From the results a hypothesis regarding the rapeseed oil-induced triglyceride accumulation of the heart is suggested.