Response of liver microsomal mixed-function oxidases to dietary linoleic acid levels in rats.

Responses of the activities of liver microsomal mixed-function oxidases (MFOs) induced by phenobarbital (PB) to dietary linoleic acid (LA) levels were investigated in rats. Diets varied in LA content (0, 1.8, 4.1, 7.0, or 13.8 energy%) were fed to rats for 16 days. The activities of MFOs did not change significantly with increasing the dietary LA level, where they reached a plateau even at 1.8 energy %, although the fatty acid composition of liver microsomal lipids reflected well that of dietary lipids. Accordingly, 2 energy % of LA as essential fatty acid seemed to be sufficient to supply the dietary requirement as assessed by the activities of PB-induced MFOs.