[The composition of fatty acids in individual classes of blood platelet phospholipids of patients with uremia].

The most important role in the formation of defects of the haemostasis in patients with uraemia is attributed to disorders of platelet activation. The important elements of phospholipid structure are saturated and unsaturated fatty acids. Five classes of phospholipids were identified in the platelets: phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), phosphatidylcholine (PC) and sphingomyelin (Sph). This paper aimed at the assessment of the fatty acid composition in individual classes of phospholipids of blood platelets in patient with uraemia. We studied 18 uraemic patients who were treated conventionally and 21 patients treated with with repeated haemodialysis. The classes of phospholipids were isolated by thin layer chromatography and the contents of fatty acids in the individual classes of of phospholipids were assessed by gas chromatography. In patients treated conventionally great differences in the contents of fatty acids in the individual classes of phospholipids were demonstrated as compared with the control group. The differences can be caused by disorders of blood plasma lipids. In general--more unsaturated fatty acids were found in the classes of phospholipids forming the outer surface of the platelets as compared to the inner surface. In haemodialysed patients the differences in the fatty acid contents compared with the control group were evidently smaller (perhaps resulting from some normalization of biochemical changes in the plasma of dialyzed patients). In this group a greater content of unsaturated fatty acids in Sph and PC was also found. The high content of unsaturated fatty acids may increase the platelet membrane fluidity and intensive lipid-protein reaction, e.g. binding of coagulation factors, so may play a role in haemostasis disturbances observed in uraemic patients.