Pre- and post-operative nitric oxide production by circulating neutrophils of patients with gastrointestinal or liver cancer

Perioperative in vitro nitrite production by circulating polymorphonuclear neutrophils (PMNs) as well as PMN iNOS and nitrotyrosine expression were investigated in gastrointestinal or liver cancer (CA) patients (n = 12) in comparison to that of cholecystectomy (CH) patients (n = 6) and healthy blood donors (n = 16). Immunoreactive bands corresponding to iNOS protein were found in PMN lysates of all investigated groups but no correlation was found between iNOS expression and nitrite production. Pronounced perioperative expression of iNOS in PMNs of CA patients was accompanied by decreased in vitro nitrite production as compared to that of CH patients. On the other hand, expression of nitrotyrosine in PMNs of CA group correlating with iNOS expression may indicate that peroxynitrite and other reactive nitrogen species are accumulated in PMNs of CA patients.