Spontaneous nonneoplastic gastric lesions in female Han:NMRI mice, and influence of food restriction throughout life.

A life span study of 900 female virgin Han:NMRI mice (300 outbred controls, 300 of a fat subline, and 300 of a lean subline) was done to determine the occurrence of spontaneous disease with ad libitum or restricted feeding. Major nonneoplastic lesions in the glandular stomach were erosions, ulcers and adenomatous hyperplasia of the fundus. Ulcers, ranging in incidence with ad libitum feeding from 5 to 9% and with food restriction from 13 to 34%, either occurred secondary to other diseases or were due to stress associated with food restriction, causing death mainly in the lean subline. Adenomatous hyperplasia was most common in the control group (41%); the frequency increased with age and was significantly reduced by food restriction. The etiology of adenomatous gastric hyperplasia is yet unknown. However, a lack of antiparietal cell antibodies, as determined by an immunofluorescent technique, indicates that an autoimmune disorder is not involved and an increase in antral gastrin cells, as determined by avidin-biotin peroxidase immunocytochemistry, suggests a hormonal involvement in pathogenesis.