The effect of feeding aflatoxin-contaminated groundnut meal, with or without ammoniation, on the development of gamma-glutamyl transferase positive lesions in the livers of Fischer 344 rats.

The detoxification of aflatoxin-containing groundnut meal by ammoniation has been investigated using weanling male and female Fischer 344 rats. Rats were fed a pelleted diet consisting of 75% groundnut meal and 25% powdered rat diet, with vitamin supplement, for a period of 90 days. The groundnut meal was either aflatoxin-free or naturally contaminated with aflatoxins, and was used untreated or after ammoniation. Body weights and food consumptions were monitored throughout the experimental feeding period. After 90 days the animals were sacrificed and the gamma-glutamyl transferase (GGT) levels in the livers assayed fluorimetrically, and the distribution of the enzyme activity determined histochemically. The results indicated that ammoniation of the aflatoxin-containing meal eliminated the development of focal GGT positive lesions in both male and female animals. However, in the female, histochemical GGT staining of hepatocytes in the periportal areas was increased by all the experimental diets compared with the unammoniated, aflatoxin-free diet. This observation was supported by the fluorimetric assays. Ammoniation of the diet led to a decreased body weight gain in all cases compared with the corresponding unammoniated diet-fed groups.