Strain Differences in Induction and Modification of Stomach Tumor Development in Mice Treated with X-irradiation

Abstract

The stomach region of male hypocatalasemic (C^b_s), C3H, and BALB mice of both sexes was irradiated once with a dose of 20 Gy of X-ray. After irradiation the C^b_s mice were administered with 0.1% hydrogen peroxide (H₂O₂) solution as their drinking water, or 10% sodium chloride (NaCl) in their diet. The resultant total tumor incidences were 50% to 100% by the end of the experiment after 13 months. More female mice died in the early phase after X-irradiation than males. Well differentiated tumors were observed in the glandular stomachs of 35 to 100% and signet ring cell carcinomas in 0 to 22% of the animals. Squamous cell carcinomas (SCCs) were most frequently encountered in BALB mice of both sexes. The present results indicate that X-ray induction of adenocarcinomas, signet ring cell carcinomas, and SCCs of the glandular stomach in CS mice is not promoted by H₂O₂ or NaCl.