Abstract: Objective To explore the sub-chronic toxicity of sodium chloride on rat by oral gavage. Methods Eighty SPF SD rats were randomly divided into control, low-dose, middle-dose and high-dose groups with half male and half female. The treatment groups were exposed to sodium chloride (low-dose group with 100 mg/kg, middle-dose with 500 mg/kg and high-dose group with 1 000 mg/kg) and the control group were exposed with pure water by oral gavage for continuous 90 days. Clinical observations, daily diet consumption and body weight of rats in each group were recorded during exposure. After exposure completed, the rats were anesthetized and blood samples were collected from abdominal aorta to test the routine blood indexes, serum biochemistry and plasma electrolytes. The main organs were dissected and weighed to calculate the organ coefficients. Histopathology changes of main organs were observed by microscopy. Results There were no difference in body weight, blood routine index, daily ration and organ coefficients between all groups (P>0.05). Serum biochemistry examination showed that, compared with the control group, the ALT and AST were decreased (P<0.05) while the TBIL and calcium content were increased (P<0.05) in middle-dose and high-dose groups. In the pathological examination of rats, pathological changes of spongy degeneration, congestion, necrosis and infiltration of liver were found in some rats in middle-dose and high-dose groups. And some male rats in middle-dose and high-dose groups also found renal?tubular calcification, thymic hemorrhage and bleeding tendency of lymph nodes. No changes of biological significance were found in the serum biochemistry examination in the control and low-dose group. No pathological lesion can been seen in the control and low-dose group. Conclusion The sub-chronic toxicity of sodium chloride by oral administration can cause blood circulatory disorder and renal deposition of calcium salt in male rat.

Key words: Sodium chloride, Rats, Sub-chronic toxicity