Polymorphonuclear leucocyte rheology and cytosolic Ca2+ content after activation in chronic renal failure

SUMMARY: We evaluated polymorphonuclear leucocyte (PMN) flow properties in patients with clinically stable chronic renal failure (CRF) and in control subjects at baseline and after activation with 4-phorbol 12-myristate 13-acetate (PMA) and N -formyl-methionyl-leucyl-phenylalanine (fMLP). Initial relative flow rate (IRFR) and clogging particles (CPs) were obtained using the St. George's Filtrometer, and PMN membrane fluidity was assessed by marking PMNs with 1-(4-(trimethylamino)phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH). PMN cytosolic Ca²⁺ concentration was determined by marking PMNs with Fura 2-AM. At baseline, CRF patients showed a significant increase only in PMN cytosolic Ca²⁺ content. After activation with PMA and fMLP, a decrease in IRFR and an increase in CP were observed in both control subjects and CRF patients, although the variation in IRFR present in the group of CRF patients was greater than in the control group. After activation with PMA and fMLP, we found a decrease in PMN membrane fluidity only in CRF patients, but no variation in PMN cytosolic Ca²⁺ concentration in either group was observed. These results provide evidence for PMN dysfunction in chronic renal failure.