LONG TERM EFFECTS OF HIGH FAT AND SUCROSE DIETS ON OBESITY AND LYMPHOCYTE PROLIFERATION IN MICE

Objective: To clarify the effect of prolonged feeding of a high-fat and sucrose, and to clarify the effect of sucrose instead of other carbohydrate on obesity and immunity in C57BL/6J mice. Methods: We investigated the development of obesity and immune cell function in four groups of mice fed high-fat, high-fat plus highsucrose, high-sucrose, and control diet for 7 months. Results: Mice fed high-fat and high-fat plus high-sucrose groups developed severe obesity. Body weight, adipose tissue weight, serum leptin, blood glucose, and insulin were significantly higher, while the level of serum soluble leptin receptor was significantly lower in mice fed high-fat and high-fat plus high-sucrose diets than in mice fed the control or high-sucrose diets. Splenocyte proliferation stimulated by T-cell mitogen (PHA, ConA, and anti-CD 3 antibody) and B-cell mitogen (LPS) was significantly lower in both obese, high-fat and high-fat plus high-sucrose groups than in control and high-sucrose groups. However, these parameters did not differ between high-fat and high-fat plus high-sucrose groups. Conclusions: Long-term feeding of high-fat diet and high-fat plus high-sucrose diet similarly induced severe obesity in C57BL/6J mice. Not only T-cell, but also B-cell function may be impaired in mice made severely obese by the high-fat or high-fat plus high-sucrose diets.