RÉSUMÉ
Nitric oxide [NO] is a molecule required for many physiological functions, produced from L-arginine by NO synthases [NOS]. It is a free radical, producing many reactive intermediates that account for its bioactivity. Sustained induction of the inducible form of NOS [iNOS] in chronic inflammation may be mutagenic, through NO-mediated DNA damage or hindrance to DNA repair, and thus potentially carcinogenic. Due to the short half-life of NO, usually its end products [nitrate or nitrite] are measured as an index of NO production. There is evidence that expression of iNOS in tumor cells, including acute myeloid leukemia and chronic lymphocytic leukemia increased. In this study, the levels of nitrate and nitrite [nitric oxide products] in the serum of patients with acute leukemia were determined. The serum levels of these compounds were measured in 40 acute leukemia patients. The results of serum nitrite and nitrate of patients were compared with corresponding values obtained in 40 healthy volunteers. These results indicate that patients with acute leukemia had a significant increase in the serum level of nitrite and nitrate