Abstract
Nutritional muscular dystrophy was induced in rats by the feeding of a diet deficient in both vitamins E and B6. Other groups of rats received this basal diet supplemented with vitamins E and B6 singly and in combination. The rats were injected with either sodium C14 formate or C14 methyl-labeled choline and the specific activities of excreted creatinine and creatine were determined. Results were similar with both of the labeled creatine presursors. The animals deficient in both vitamins E and B6 excreted large amounts of creatine. The specific activity of creatinine excreted following the injection of either radioactive precursor was elevated in the rats deficient in both vitamins. The specific activity of creatine excreted by the doubly deficient animals following the administration of sodium C14 formate exhibited the same specific activity as did the creatinine. It is concluded that the creatinuria which accompanies nutritional muscular dystrophy in the rat is the result of an inability of the muscle to retain creatine after its incorporation.