The effect of butylated hydroxytoluene, butylated hydroxyanisole and octyl gallate upon liver weight and biphenyl 4-hydroxylase activity in the rat

Abstract
When a diet containing butylated hydroxytoluene at levels of 0·01 to 0·5% is fed to growing male rats for 12 days, body weight is not affected, but liver weight is increased. The activity of liver microsomal biphenyl 4-hydroxylase is also increased by these concentrations of butylated hydroxytoluene except the lowest level of 0·01% (100 ppm). Butylated hydroxyanisole at 0·1 and 0·25% of the diet did not affect liver weight or the enzyme activity, but at 0·5% it caused some increase in enzyme activity but not in liver weight. At the level of 0·5%, butylated hydroxytoluene given for a single day caused an increase in liver weight which was observed two days later and persisted for three days after which time the liver weight did not differ from controls. Enzyme activity was not significantly altered by 0·5% butylated hydroxytoluene fed during a single day. Octyl gallate fed at 0·5% of the diet for 9 days did not affect liver weight or enzyme activity. High fat diets with or without 0·01% butylated hydroxytoluene fed for 12 days did not increase liver weight, but did increase biphenyl 4-hydroxylase activity.