Enzymmuster gesunder skelett-, herz- und glatter muskulatur des menschen sowie ihrer pathologischen veränderungen mit besonderer berücksichtigung der progressiven muskeldystrophie (ERB)

Abstract

Measuring the activities of 9 enzymes from the metabolism of carbohydrates (LDH, MDH, SDK, ALD), proteins (GOT, GPT, GLDH) as well as from energy transmission (CK, MK), three types of human skeletal muscles can be distinguished: the red, white and intermediate type. In the red skeletal muscle (m. pectoralis and the abdominal muscles) glucose metabolism is mainly aerobical ( Q LDH/MDH = 0.345). Transaminase (GOT, GPT) activity is high, but that of energy transformation (CK, MK) and of NH 3 elimination (GLDH) is lower than in the white skeletal muscle. In the white skeletal muscle (m. deltoides brachialis, m. semimembranaceus) glucose is metabolized anaerobically as well as aerobically ( Q LDH/MDH = 0.914). Transaminase activity is lower than in the red muscle, while energy transforming activity (CK), LDH activity and NH 3 elimination (GLDH) activity are the highest of the three skeletal muscle types. In the intermediate type of human skeletal muscle (m. quadriceps femoris, m. biceps brachialis, m. quadratus femoris) anaerobical glycolysis is lowest of the three types. Aerobical glucose metabolism and transaminase activity are approximately as high as in the white muscle. NH 3 elimination is in the same range as in red muscle, and energy transforming activity lies between that of the red and white skeletal muscle. Glycolytic activity of human heart muscle is as high as in the red muscle, but GOT activity is twice as high. NH 3 elimination (GLDH) equals that of the white muscle. Energy transforming activity is lower than in skeletal muscle. Glycolytic activity of human heart muscle is as high as in the red muscle, but GOT activity is twice as high. NH 3 elimination (GLDH) equals that of the white muscle. Energy transforming activity is lower than in skeletal muscle. In the smooth muscle of the gastrointestinal tract and the myometrium the specific activity of enzymes from carbohydrate and protein metabolism, as well as from energy transformation is lowest. Using the ratio of energy-transforming activities (CK) and the oxidative (anaerobical) metabolic activity of glucose (MDH, LDH), the different sorts of human muscle can be classified, in diminishing order of the quotients, as follows: white, intermediate and red skeletal muscle, heart muscle and smooth muscle. Pathological changes in human skeletal, heart and smooth muscle (progressive muscular dystrophy Duchenne, X-rays, hypoxaemia, myocardiac hypertrophy, diffuse hyperplasia of the myometrium, myosarcoma) raise the anaerobical glycolysis and depress aerobical glucose metabolism, and, for the most part, diminish the energy transformation of ATP produced by aerobical glucose metabolism. A possible explanation for this would be an underlying genetical type of unspecific control mechanism common to the muscles. Further studies are required to substantiate the results. Glycolytic activity of human heart muscle is as high as in the red muscle, but GOT activity is twice as high. NH 3 elimination (GLDH) equals that of the white muscle. Energy transforming activity is lower than in skeletal muscle. In the smooth muscle of the gastrointestinal tract and the myometrium the specific activity of enzymes from carbohydrate and protein metabolism, as well as from energy transformation is lowest. Using the ratio of energy-transforming activities (CK) and the oxidative (anaerobical) metabolic activity of glucose (MDH, LDH), the different sorts of human muscle can be classified, in diminishing order of the quotients, as follows: white, intermediate and red skeletal muscle, heart muscle and smooth muscle. Pathological changes in human skeletal, heart and smooth muscle (progressive muscular dystrophy Duchenne, X-rays, hypoxaemia, myocardiac hypertrophy, diffuse hyperplasia of the myometrium, myosarcoma) raise the anaerobical glycolysis and depress aerobical glucose metabolism, and, for the most part, diminish the energy transformation of ATP produced by aerobical glucose metabolism. A possible explanation for this would be an underlying genetical type of unspecific control mechanism common to the muscles. Further studies are required to substantiate the results.