The effect of retinol on the changes of lipid composition in serum of rabbit

Serum retinol is considered to increase when the beef cattle is fattened up or in a muscle marbling process. We examined the effects of retinol on the total lipids, triglycerides, phospholipids, cholesterols and lipid peroxides using rabbits. The animals were given 15,000 or 150,000 IU/kg of retinol (retinyl palmitate) intramuscularly once every 4 days for 48 days. When treated with 150,000 IU/kg of retinol, animals showed changes in the serum concentrations of total lipids, triglycerides, phospholipids, cholesterols and lipid peroxides. In particular, lipid peroxides remarkably increased. These results indicated that retinol accelerated the oxidation of serum lipids and that the effect of retinol was more prominent in unsaturated fatty acids than in saturated fatty acids. Furthermore, it was suggested that a large amount of administrated retinol may cause qualitative change of lipid composition in muscle.