NOS2A gene polymorphism and its association with nitric oxide production in peripheral blood leukocytes of normal individuals

ABSTRACT

In peripheral blood polymorphnuclear and mononuclear cells Nitric Oxide [NO] could be synthesized by an enzyme called inducible NO synthase [iNOS]. iNOS gene [NOS2A] is located on chromosome 17 at position 17q11.2-q12. NO is released during inflammatory responses. In the present studies the frequency of NOS2A gene polymorphisms and their effects on NO production were investigated in the Peripheral Blood polymorphonuclear and mononuclear cells of normal individuals. In this study the frequency of NOS2A gene polymorphisms at positions -1659 C/T and +150 C/T of 232 normal subjects were investigated using PCR-Allele specific and PCR-RFLP methods, respectively. To study the effect of 1659C/T and +150C/T polymorphisms on NO production, polymorphonuclear and mononuclear cells of peripheral blood of 92 normal subjects were isolated and then stimulated by E.coli culture supernatants [ATCC 25922] for induction of iNOS enzyme and NO production. After 24h, the level of NO production in the culture supernatant were measured by Griess reaction. Polymorphisms as mentioned above were also studied in these normal cases. The results showed no significant difference in the level of NO production of various genotypes in the polymorphonuclear and mononuclear cells of peripheral blood of normal subjects. Our results indicated no significant correlation between NOS2A genotypes and NO production. No significant difference was observed between Gambia and China normal population and normal subjects of this study in NOS2A- 1659 C/T and +150 C/T polymorphisms. In Iran these differences are due to the genetic and ethnic differences among the studied populations, which indicates the importance of NOS2A polymorphism in the NO production, suggesting further studies in other ethnic groups