On the significance of the hypertrophy of the smooth endoplasmic reticulum in liver cells after administration of drugs

A large increase of the smooth endoplasmic reticulum (SER) is produced in the hepatic cell following the administration of numerous drugs, some of which also have an injurious effect on the liver, while others are not capable of producing overt hepatic lesion. Morphological modifications of the SER produced by the various drugs are practically identical. However, the significance of the phenomenon is not clear, because in some cases it is accompanied by an increase, in others by an inhibition, of microsomal metabolic activity. We think that SER hypertrophy may be produced by one and the same mechanism and that all substances capable of producing SER hypertrophy may act as inducers of microsomal enzymes, thus stimulating hepatic cell to produce both endoplasmic reticulum membranes and enzymes. However, some of these substances, or their metabolites, are inhibitors of protein synthesis. In this case synthesis of new enzyme molecules is impossible and the response of the hepatic cell to the pharmacological stimulus is limited to the formation of the SER membranes.