Metabolism of AMP in Muscle Extracts from Patients with Deficient Activity of Myoadenylate Deaminase
In a number of patients with muscle weakness, cramps, and easy fatigability, deficient activity of adenylate deaminase (AMPD) in muscle tissue has been demonstrated1,2. The enzyme defect seems to be correlated with failure to release ammonia from muscle during exercise. Since a simultaneous depletion of adenine nucleotides in muscle tissue has been detected, disruption of the purine nucleotide cycle has been postulated as the pathogenetic mechanism. This hypothesis, however, fails to account for the problem, how deficiency of a catabolic enzyme can result in substrate depletion. Furthermore, association of AMPD-deficiency with variable clinical conditions has raised doubts about the primary role of the enzyme defect2,4.
KeywordsDouble Reciprocal Plot Hypoxanthine Phosphoribosyltransferase Deficient Activity Easy Fatigability Purine Nucleotide Cycle
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- 4.S. DiMauro, A.F. Miranda, A.P. Hays, W.A. Franck, G.S. Hoffman, R.S. Schoenfeldt, and N. Singh, Myoadenylate deaminase deficiency. Muscle biopsy and muscle culture in a patient with gout. J. Neurol. Sci. 48: 668 (1980).Google Scholar
- 5.D.E. Atkinson, “Cellular Energy Metabolism and its Regulation”, Academic Press, New York (1977).Google Scholar
- 6.P. Santavuori and J. Leisti, Muscle, eye and brain disease (MEB), in: “Population Structure and Genetic Disorders”, A.W. Eriksson, H. Forsius, H.R. Nevanlinna, P.L. Workman, and R.K. Norio, eds., p. 647, Academic Press, London (1980).Google Scholar