Polymorphonuclear leukocyte rheology before and after chemotactic activation in different clinical conditions

We examined at baseline and after activation with N-formyl-methionyl-leucyl phenylalanine (fMLP) the polymorphonuclear (PMN) leukocyte rheology express ed not only as filtration parameter (using the St. George's Filtrometer) bu t also as membrane fluidity (employing the fluorescent probe TMA-DPH) and c ytosolic Ca2+ concentration (adopting the fluorescent probe Fura-2AM) in a group of subjects with vascular atherosclerotic disease (VAD), in a group o f VAD subjects with type 2 diabetes mellitus (DM), in a group of type 1 dia betics, in a group of type 2 diabetics, in a group of hypertensives and in a group of subjects with chronic renal failure (CRF), The obtained results show that after activation the PMN filtration paramete r (IRFR) was significantly and constantly reduced in normals and in all the examined groups although this reduction was more evident in diabetics of b oth types, in hypertensives and in CRF subjects. The PMN membrane fluidity after activation decreased significantly only in type 1 diabetics and in CR F subjects while PMN cytosolic Ca2+ content did not show any significant va riation in normal controls and in CRF subjects. These data underline how the PMN rheological pattern needs to be examined a t baseline and after activation, even if the mechanisms of these variations are not always demonstrated.