Effect of cycloheximide on hepatic microsomal lipids as a function of age in rats

Cycloheximide, at a non-lethal dose of 2 mg/kg body weight, increases the level of total lipids and major lipid fractions in total, rough and smooth liver microsomes obtained from suckling, adult and old rats, but not in the newborns. The rates of increase differ in the different age-groups and fractions. Total lipids and phosphatidyl choline of rough and smooth microsomes in adult rats reach control levels at 6 h after the antibiotic treatment. Phospholipid fractions of old rats tend to approach control levels by 6 h after treatment whereas cholesterol levels remain relatively high. Total lipids, phosphatidyl choline and phosphatidyl ethanolamine of total, rough and smooth microsomes show significant quantitative differences during development.