Muscle Phosphorus in Nutritional Muscular Dystrophy in Rabbits*

Rabbits and guinea pigs upon certain diets develop an extreme degeneration of the skeletal muscles (15, 22). The onset of these muscle lesions may be delayed or prevented by the inclusion of vegetable oils in the diet (21, 26, 31) or by vitamin E concentrates (23). In dystrophic muscle the creatine content is lower than normal and roughly proportional to the amount of pathological degeneration (14, 27) ; there is an increase in moisture and a decrease in total nitrogen (14), an increase in the rate of oxygen consumption (38, 21), a decrease in glycogen, total acid-soluble phosphorus, and fractions thereof, and an increase in cholesterol content (27), a gain in sodium chloride and a corresponding loss in potassium and magnesium, and an increase in calcium (10, 25). In order to describe dystrophic muscle more completely, analyses of total phospholipid, total acid-soluble phosphorus, and total inorganic orthophosphate phosphorus were made upon the muscle of about 50 normal rabbits and the same number of rabbits in various stages of nutritional muscular dystrophy. Determinations of phosphocreatine and inorganic orthophosphate phosphorus in resting muscle were carried out in a few animals. The values obtained were compared with the extent of pathological degeneration and creatine content.