Nine non-diabetic patients with peripheral arterial disease were investigated as for (i) their red cell deformability, using a filterability measurement technique and (ii) the in vitro phosphorylation of their red cell membrane proteins, with special reference to cytoskeletal proteins. The deformability appeared significantly (p < 0.01) reduced in the patients. However, the phosphorylation of erythrocyte membrane proteins was strictly normal. Therefore, the molecular basis for decreased deformability must not reside in some acquired alteration of the cytoskeleton, in vitro phosphorylation being a sensitive probe of cytoskeletal protein organization.
