Muscle lipids in Duchenne muscular dystrophy.

The lipids of muscle and adipose tissue from normal males and of muscle from males with Duchenne muscular dystrophy were investigated. Triglyceride, the major neutral lipid, showed similar fatty acid compositions in all tissues examined. When the phospholipids of dystrophic muscle and of normal adipose tissue were compared with those of normal muscle, it was found that there was an increase in the proportion of sphingomyelin in dystrophic muscle, while adipose tissue had higher proportions of sphingomyelin and lysophosphatidylcholine but lower choline phosphoglyceride. In dystrophic muscle only small alterations from normal were observed in the fatty acid compositions of the individual phospholipids, whereas the phospholipids of adipose tissue had quite distinctive fatty acid compositions. An atrophic muscle sample resulting from poliomyelitis consisted almost entirely of connective tissue and fat and had a phospholipid composition similar to that of adipose tissue. From a comparison of the results for all the types of tissue studied, it is evident that the increase in sphingomyelin in dystrophic muscle biopsies and the changes in the fatty acid compositions of individual phospholipids may be accounted for by the increased amounts of fat and connective tissue which are present in dystrophic muscle samples. In a case each of polymyositis, limb girdle muscular dystrophy and an autosomal recessive form of muscular dystrophy, the results obtained for the phospholipid composition of the muscle sample were also normal or consistent with some contamination from fat and connective tissue.