Lack of Some Muscle Proteins in Serum of Patients With Duchenne Dystrophy

Abstract

AN'abnormal increase in the activity of several serum enzymes is one clue to the nature of the biochemical abnormality in Duchenne muscular dystrophy. The increased serum enzyme activity is thought to occur because enzyme protein molecules are released from muscle, and it has been inferred that the fundamental disorder is an abnormality of the muscle membrane which permits pathological leakage of large molecules. If this were true, it might be expected that other cytoplasmic constituents of muscle would also be found in the serum. We have been studying phosphofructokinase (PFK), phosphorylase (PPL), and myoglobin in normal human muscle diseases. Appropriate techniques were applied to the serum of patients with Duchenne dystrophy but PFK and myoglobin were not found at all and the activities of PPL were very low, as will be described in detail. Methods The patients were all ambulatory males below age 10 years, with overt manifestations of