Studies on the Blood and Tissues in Nutritional Muscular Dystrophy

Abstract

In rabbits suffering from nutritional muscular dystrophy we do not find the characteristic zig-zag sugar tolerance curve generally occurring in human subjects with muscular dystrophy. The glycemic curve of the dystrophic rabbit differs, however, from that of the normal rabbit in that it rises slower, reaching a peak in about twice the length of time, does not attain such a high level and slopes off more gradually than in the latter. The analyses of a number of fasting bloods from both normal and dystrophic rabbits fail to indicate any appreciable variation between the two groups so far as the sugar, lactic acid, total acid soluble phosphorus and the partition of its several fractions are concerned. The lipid-P and cholesterol content of the blood show marked increases in the diseased animals, the increase being proportional to the degree of the dystrophic change. When by proper dietary means the regenerative process in the dystrophic muscle is initiated leading to recovery from the disease the concentration of the lipid-P and particularly of the cholesterol in the blood decreases again, returning ultimately to the normal values. The glycogen content of the skeletal muscles from rabbits suffering from nutritional muscular dystrophy is very greatly reduced, the reduction being proportional to the extent of the degenerative process. The absolute concentration of the acid soluble phosphorus and its different fractions is decreased in the dystrophic muscles, the decrease being proportional to the degree of dystrophy, but the relative distribution of the various phosphorus fractions is practically unaltered and is nearly the same as in the normal muscles. The creatine content of the muscles diminishes parallel to the development of dystrophy but the portion of the total creatine esterified in the form of phosphagen is considerably greater in the dystrophic than in the normal muscles. The cholesterol content of the skeletal muscles is greatly increased in dystrophic rabbits. In the muscles of the extremities the cholesterol content may become even more than doubled while in the muscles of the trunk it is not so large. The cholesterol content of the muscles from visceral organs (heart, stomach, intestine) is practically unchanged, which is true also for the brain and kidneys, but in liver, lung and spleen there is a variable but definite decrease.