The feeding of diets containing up to 4% monosodium glutamate to rats for 2 years

Abstract

Charles River CD rats were fed diets containing either 2.05% w/w sodium propionate or 1, 2 or 4% w/w monosodium glutamate (MSG) for 104 weeks. There were no adverse effects upon bodyweight gain, economy of food consumption, haematology, blood chemistry, organ weights or mortality by comparison with control rats receiving the basal diet. Water consumption, urinary volume and sodium excretion were increased at 2.05% sodium propionate or 4% MSG, and this appeared to be reflected in an increased incidence and earlier onset of spontaneous subepithelial basophilic deposits in the renal pelvis among treated rats. Focal mineralization at the renal corticomedullary junction occurred with equal frequency in all groups, including untreated controls. There were no other histological findings of significance.