EFFECTS OF CHRONIC HYDROCHLORIC AND LACTIC ACID ADMINISTRATIONS ON FOOD INTAKE, BLOOD ACID-BASE BALANCE AND BONE COMPOSITION OF THE RAT

In experiment 1, weanling rats were given, for 7 weeks, a commercial rat diet supplemented with hydrochloric acid at levels up to 560 mmol.kg -1 dry matter. The supplement increased water intake but did not significantly affect food intake, live-weight gain, blood haemoglobin and haematocrit values or acid-base balance. In experiment 2, adult rats were given, for 9 weeks, a commercial rat diet supplemented with hydrochloric acid at levels up to 1250 mmol.kg -1 dry matter. Food intake and liveweight gain were not affected by hydrochloric acid concentration up to 625 mmol but at 938 and 1250 mmol.kg -1 they were considerably reduced and there was 100% mortality of the rats. In experiment 3, weanling rats were given, for 12 weeks, a commercial rat diet supplemented with hydrochloric or lactic acid each at 300, 600 and 900 mmol.kg -1 dry matter. Lactic acid at the three levels and hydrochloric acid at the two lower levels did not affect food intake or liveweight gain and had only a slight effect on blood acid-base balance. At a dietary concentration of 900 mmol.kg -1 dry matter, hydrochloric acid decreased food intake, induced a mild degree of metabolic acidosis and resulted in 30% mortality of the rats. In the three experiments, the acid treatments did not directly affect the length or composition of the femur of the rats.