Histochemical study of induced gastrointestinal tract tumors in strain A/jax (lung tumor susceptible) mice.

Abstract

Tumors were induced in the small intestine, forestomach, and lungs of strain A/jax mice by feeding olive oil emulsions containing 20-methylcholanthrene. Histochemical methods were used to determine the occurrence and distribution of acid and alkaline phosphatase in the tissues of the mice. The tumors generally showed a complete absence of alkaline phosphatase and widely varying quantities of acid phosphatase in the cytoplasm of the individual cells. Tumors of the small intestine and forestomach showed a high concentration of alkaline phosphatase in the submucosal zone immediately beneath the neoplasm. No enzyme changes from normal were detected in lesions considered histologically to be premalignant. Some groups of mice were fed iron choline citrate or ethylenediamine tetraacetic acid, tetrasodium salt in addition to 20-methylcholanthrene. These substances produced no effect on the rate of growth or numbers of tumors induced, nor on the acid and alkaline phosphatase reactions.