Erythrocyte cation-activated adenosine triphosphatases in Duchenne muscular dystrophy.
The cation-stimulated adenosine triphosphatase (ATPase) activities of erythrocyte ghosts and erythrocyte ghost plasma membrane fragments of patients with Duchenne muscular dystrophy (DMD) were compared with activities in age-matched normal male controls. DMD Mg++-stimulated ATPase activity was within the normal range. The specific activity of DMD erythrocyte ghost Na+,K+-stimulated, Mg++-dependent ATPase was also normal, and was inhibited by 10(-4) M ouabain to an extent comparable with controls. Ca++-stimulated, Mg++-dependent ATPase activity of DMD erythrocyte ghost plasma membrane fragments, assayed at 0.5 mM free Ca++, was 21% above that in age-matched male controls (n = 22, 2-tailed paired t-test, P less than 0.01). Kinetic studies indicated that the DMD erythrocyte Ca++-stimulated, Mg++-dependent ATPase has greater affinity for MgATP than the enzyme in control erythrocytes.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000293:Adolescent; D002118:Calcium / Q000378:metabolism; D002413:Cations, Divalent; D002414:Cations, Monovalent; D002648:Child; D002675:Child, Preschool; D004910:Erythrocyte Membrane / Q000201:enzymology*; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D007223:Infant; D008274:Magnesium / Q000378:metabolism; D008297:Male; D009136:Muscular Dystrophies / Q000097:blood / Q000201:enzymology*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism
D002413:Cations, Divalent; D002414:Cations, Monovalent; D012964:Sodium; D000251:Adenosine Triphosphatases; D008274:Magnesium; D011188:Potassium; D002118:Calcium