Effect of short-term administration of sodium saccharin on rhesus monkeys.

Sodium saccharin (NaS) was incorporated into biscuits or the drinking-water and fed to rhesus monkeys at progressively increasing doses in order to determine the maximum dose that the monkeys would voluntarily consume and/or tolerate. Very little rejection of NaS-treated biscuits or drinking-water was observed. However, severe diarrhoea which precluded further treatment occurred when the dose of NaS reached 8.0% (approximately 1600 mg/kg body weight/day) in the biscuits and 0.48% (approximately 900-2400 mg/kg/day) in the drinking-water. An increase in fluid intake occurred in monkeys in both treatment groups. An increase in urine volume and a decrease in urine osmolality occurred in monkeys fed NaS in the drinking-water. No effects on body weight, food consumption or urine pH were observed in monkeys in either treatment group. All animals rapidly recovered when they were given untreated biscuits or water. Therefore, although monkeys will voluntarily consume rather high doses of NaS incorporated into biscuits or drinking-water, adverse effects on their general well-being preclude such administration for more than a few days.