Abstract
In rats, administration of phenobarbital, 3-methylcholanthrene, spironolactone, cyproterone acetate or pregnenolone-16a-carbonitrile causes proliferation of the smooth-surfaced endoplasmic reticulum (SER) in hepatocytes, without producing marked changes in other cell organelles. The significance of this SER increase and its relationship to microsomal enzyme induction are discussed.