Tissue lipids in calves suffering from muscular dystrophy.

Abstract

1. Lipids of the heart muscle, skeletal muscle and liver were investigated in healthy calves and in calves suffering from enzootic muscular dystrophy with special regard to the fatty acid composition of the phospholipids and triglycerides. 2. Healthy young calves and older calves differed in the fatty acid composition of these tissues. The tissue phospholipids of healthy young calves contained less linoleic acid and more monounsaturated fatty acids than those of older calves. Of the saturated fatty acids, palmitic acid content tended to be higher in young calves and stearic acid content tended to be higher in older calves. 3. The stearic acid content of tissue triglycerides was lower in young calves than in older calves. 4. Fatty aldehydes were present in the phospholipid fraction of the heart muscle and of the skeletal muscle. Stearaldehyde content was higher in older calves than in young calves. 5. In calves with muscular dystrophy definite changes in the fatty acid composition of the phospholipids were found. In young calves the content of linoleic acid was higher and that of monounsaturated fatty acids lower in tissues of diseased animals than in the corresponding tissues of healthy controls. Both in young and older calves arachidonic acid content was higher in the degenerated areas of the skeletal muscle than in the healthy controls. 6. Possible relationships between the tocopherol and arachidonic acid contents of the tissues are discussed. 7. In the triglyceride fraction the differences between diseased and healthy tissues were less significant than in the phospholipid fraction in young calves. In older calves no significant differences were found. 8. An increase in lipid content was found in the degenerated areas of the skeletal muscle and a decrease in livers from diseased animals. An increase in free cholesterol was found in the degenerated areas of the skeletal muscle. The triglyceride content of livers from diseased animals was decreased. The relative proportion of phospholipids was less in skeletal muscle and higher in liver of diseased animals than in the corresponding tissues of healthy controls.