EFFECTS OF CHRONIC ORAL-ADMINISTRATION OF ERYTHROSINE IN MONGOLIAN GERBIL

Approximately equal numbers of male and female Mongolian gerbils, Meriones unguiculatus, were given erythrosine (FD and C [Food, Drug and Cosmetic] Red No. 3, a dye widely used in foods, drugs and cosmetics) by diet and by oral intubation. In the dietary study, 4 groups evenly divided by sex were treated for 105 wk at levels of 0, 1, 2 or 4%. In the intubation study, 4 groups were intubated by stomach tube twice weekly for 97 wk with an aqueous solution at levels of O, 200, 750 or 900 mg/kg. Clinical effects of dietary administration were depression of the hematocrit value, leukocyte count, reticulocyte count and Hb level, an a dose-related loss of weight, ranging from mild in groups fed 1% to marked in groups fed 4%. The dietary study also showed that dose-related changes occurred in the thyroid of animals fed the 1-4% diets. These changes were characterized by the enlargement, with increased storage of colloid, of a majority of the follicles, associated with less prominent but consistent foci of very small follicles (microfollicles) and, in a few animals, focal hyperplasia and intraluminal and interstitial leukocytic infiltration. Although there was a slight increase in follicular size in the thyroids of gerbils given 900 and 750 mg/kg by intubation, a definite effect similar to that in the dietary study was not found. Evaluation of the effect on the liver was complicated by the presence in the controls of multiple granulomas composed primarily of epithelioid cells surrounded by lymphocytes. Although special diagnostic procedures, including stains for microorganisms, failed to identify the cause, a microbial etiology was suspected, as this is most common for this type of lesion. In both studies, there was more granulomatosis in the controls than in the treated animals, but in the intubation study there was no evidence of a relation to dose.