Erythrozytenlipide bei progressiver muskeldystrophie

Abstract 1. 1. The red blood cell lipids in different forms of human muscular dystrophy (m.d., 29 cases) were estimated and a significant increase of the sphingomyelin content was found in x-chromosomal and autosomal malignant m.d. In these cases sphingomyelin was the main fraction of the phospholipids. Plasmalogens showed no variation. 2. 2. The fatty acid pattern of phosphatidylethanolamine (PE) and sphingomyelin (Sph) from erythrocytes in m.d. was significantly altered: in PE of m.d. the dimethyl acetals were increased, arachidonic acid was diminished. In Sph of m.d., the fatty acids 16:0, 24:2 and 18:2 were decreased and the percentage of stearic acid was increased. The composition of fatty acids in the corresponding fractions in the serum was not altered. 3. 3. The influx of linoleic acid and the incorporation of this fatty acid in phosphatidylcholine (PCh) and PE in erythrocytes of m.d. during incubation in vitro was increased, the reactivity of palmitic and stearic acids was not different from the controls. 4. 4. In the pooled bioptic samples of three cases of m.d., the fatty acid pattern of PCh, PE, Sph and lyso-PCh was estimated. Remarkable differences as compared to normal muscle were found. 5. 5. The results are discussed in the light of the thesis that the primary defect in m.d. concerns the specific incorporation of linoleic acid during the de novo synthesis of PCh in muscle. Possible mechanism of variation of the pattern of fatty acids in red blood cell phospholipids are discussed considering the fact that Sph has a lower turnover than PCh and PE.