Myotonic muscular dystrophy: defective phospholipid metabolism in the erythrocyte plasma membrane.
Myotonic muscular dystrophy (MyD) is a systemic genetic disorder that is thought to result from a generalized cellular membrane defect although the exact nature of this defect is unknown. This study examines two calcium-dependent membrane processes that have been observed in erythrocytes from healthy individuals: calcium-stimulated phosphatidic acid accumulation and calcium-induced potassium leak. We find that erythrocytes from MyD patients, in contrast to controls, have markedly impaired phosphatidic acid accumulations while maintaining normal potassium leaks. The calcium uptakes and ATP contents of MyD erythrocytes are not different from controls. We conclude that phospholipid metabolism is altered in MyD erythrocytes. The specificity of this abnormality and its relationship to altered muscular function are not known.
D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008563:Membrane Lipids / Q000378:metabolism*; D009224:Myotonia Congenita / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism
D008563:Membrane Lipids; D010712:Phosphatidic Acids; D011188:Potassium; D002118:Calcium