Platelet membrane fluidity, cholesterol/phospholipid ratio and cytosolic Ca2+ concentration in diabetes mellitus and in vascular atherosclerotic disease

We examined the platelet membrane fluidity (obtained by marking resting pla telets with TMA-DPH), the platelet membrane cholesterol/phospholipid (C/PL) ratio (obtained employing the column chromatography) and the platelet cyto solic Ca2+ concentration (obtained marking resting platelets with the fluor escent probe Fura 2-AM) in type 1 and 2 diabetics without macrovascular com plications, in type 2 diabetics with macrovascular complications and in sub jects with vascular atherosclerotic disease (VAD). Platelet membrane fluidi ty did not distinguish normals from diabetics of type 1 and 2; this platele t membrane property was reduced in diabetics of type 2 with macrovascular c omplications and in VAD subjects. Platelet membrane C/PL ratio and cytosoli c Ca2+ concentration did not distinguish normals from each group of patient s studied, Platelet membrane fluidity was significantly related to the C/PL ratio only in type 2 diabetics with macrovascular complications. In conclu sion, we found a decrease of platelet membrane fluidity in clinical conditi ons characterized by macrovascular damage, and this abnormality was not ass ociated with alterations of the membrane C/PL, ratio or cytosolic Ca2+ conc entration.