Biochemical Changes in Progressive Muscular Dystrophy: III. Nucleic Acid, Phosphorus and Creatine Metabolism in the Muscle, Liver and Brain of Rabbits Maintained with a Choline-Deficient Diet

Abstract

Rabbits maintained with a choline-deficient diet developed weakness in the skeletal muscle, lost body weight, and excreted more creatine and less creatinine in the urine. In the muscle of such severely affected animals a threefold increase in the concentration of DNA and RNA were observed. In the liver and brain, these concentrations decreased by 20 to 30%. The distribution pattern of phosphorus in the various acid-soluble and acid-insoluble fractions was also altered. Total phosphorus (TP), total inorganic phosphorus (TPi) and total acid-soluble phosphorus (TASP) of the muscle decreased by 28, 46 and 47%, respectively. Total acid-insoluble phosphorus (TAIP) did not show any change. In the liver, TP, Pi, TASP and TAIP all decreased. ATP and creatine were also reduced considerably in the affected muscles of such animals. In the liver and brain, creatine concentration was increased by 400 and 16%, respectively. An increase in ATP concentration was noted in the liver and brain of such animals. The present work illustrates the similarity between the various secondary biochemical changes that can be observed in the muscles of experimental animals with nutritional and hereditary dystrophy.