The Effects of Vitamin B6 Deficiency on Stored Fuel Utilization During 3 days Fasting or 6 days underfeeding in Rats

The effects of vitamin B6 deficiency on energy utilization during fasting or underfeeding were studied in rats. Fifteen rats were fed a vitamin B6 deficient(-B6) diet and another 15 rats wee fed a control (+B6) diet. These rats were fed for 5 weeks with respective diet, and then subdivided into 3 groups : non-fasted group, fasted group, underfed group. Rats of the fasted group were fasted for 3 days and those of underfed group for 6 days. At the respective time (non-fast, 3 day-fast, 6 day-underfeed at 5 weeks), animals were sacrificed. Feed efficiency ratio of - B6 rats was significantly lower than that of +B6 rats. In - B6 rats, the liver and kidney weights were significantly heavier than those of +B6 rats but spleen and heart weights were not. In non-fasted group, liver protein and triglyceride level of - B6 rats were significantly higher than that of +B6 rats. After - B6 rats were fasted for 3 days, plasma free fatty acid level was significantly lower but liver glycogen level was higher than that of +B6 rats and muscle protein level of +B6 was decreased while that of - B6 was not changed. Vitamin B6 deficiency had little effect on the energy utilization with 6 days underfeeding. These results suggest that vitamin B6 deficiency may impair the utilization of stored fuel during fasting.