Short-term toxicity study of metatartaric acid in rats.

Groups of rats were given metatartaric acid in the drinking-water in concentrations of 0 (control), 0.1, 0.5 or 3.0% for 18 wk. No effects associated with treatment were seen in the results of the haematological examinations and serum analyses. The treated animals consumed less water and food than the controls, probably because of the unpalatability of the test material. Administration of the 3% solution was associated in males with a reduced growth rate, some impairment of urine-concentrating ability during prolonged water deprivation (also seen in males on 0.5%) and histopathological changes in the stomach indicative of an inflammatory response in the submucosal layer. Both sexes of the 3% group showed an increase in relative kidney weight, without accompanying histopathological change. The no-untoward-effect level in this study was 0.1% metatartaric acid in the drinking-water, equivalent to a mean daily intake of 80 mg/kg body weight in the males and 130 mg/kg in the females.