Electron microscope evidence of mitochondrial change in small intestine associated with administration of 20-methylcholanthrene.

Abstract

Summary Strain A/Jax male mice were fed 20-methylcholanthrene in an emulsion form to produce carcinoma of the small intestine. Animals were sacrificed weekly, and portions of the small intestine mucosa were removed for study in the electron microscope. One group of animals was not sacrificed until tumors had developed in the small intestine. Attention was focused primarily on the small intestinal villus cells. When compared with control animals, intracellular changes in pretumor animals fed 20-methylcholanthrene appeared to be limited mainly to slight disorganization of the endoplasmic reticulum. Large, dense bodies in the mitochondria of cells, which were interpreted as being pre-invasive, were the most striking observation. The actual carcinoma cells generally showed an irregular nuclear membrane and numerous finger-like processes of the outer cell membrane.