Dietary factors and aflatoxin toxicity: I. comparison of the effect of two diets supplemented with aflatoxin B1 upon two different strains of rats

Abstract

AbstractPrevious studies in this laboratory with rats fed low levels of aflatoxin as a component of peanut discards, suggested either a strain tolerance for aflatoxin or a possible protective factor present in the diets used. In this study, two strains of rats, the Charles‐River strain and the former USC strain, were used to test the effect of 1.7 ppm purified aflatoxin B1 included for 3 months in two different diets; one previously used in this laboratory and one used by other investigators in aflatoxin studies. After an experimental period of either 12 or 18 months, growth, mortality, gross pathology, and organ wt were measured, and histopathological examination and biochemical analyses were performed. Plasma and liver cholesterol levels, total liver lipids, and fatty acids in the various lipid fractions of plasma, liver, and liver tumor lipids were measured. Both strains of rats proved to be susceptible to aflatoxin toxicity at this level as manifested by the appearance of hepatomas; however, liver involvement was more extensive in the Charles‐River rats. The diet used by other investigators produced symptoms similar to those observed as a result of essential fatty acid deficiency and also affected the response to aflatoxin through an aggravation of symptoms, i.e. an inhibition of growth and increased size and severity of the liver tumors.