Enhancement of macrophage microbicidal activity: supplemental arginine and citrulline augment nitric oxide production in murine peritoneal macrophages and promote intracellular killing of Trypanosoma cruzi.
AUTOR(ES)
Norris, K A
RESUMO
The generation of nitric oxide (NO) is largely responsible for the intracellular killing of Trypanosoma cruzi by activated macrophages. The present study was carried out to determine whether the production of NO by activated murine macrophages cultured in physiologic levels of arginine can be augmented by increasing the availability of arginine, the substrate for NO biosynthesis. Increased exogenous arginine or citrulline resulted in a significant increase in NO production and complete clearance of the parasites by activated macrophages. As citrulline fully substituted for arginine in supporting NO production and trypanocidal activity, these results demonstrate the expression of a highly active citrulline-NO cycle in activated macrophages and that levels of arginine in plasma are limiting with respect to both NO production and trypanocidal activity in these cells. The results indicate that increasing plasma substrate levels for both arginine and NO biosynthesis may represent a means of enhancing microbicidal activity in vivo.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=173377Documentos Relacionados
- β-Chemokines Enhance Parasite Uptake and Promote Nitric Oxide-Dependent Microbiostatic Activity in Murine Inflammatory Macrophages Infected with Trypanosoma cruzi
- Differences in microbicidal activities of human macrophages against Toxoplasma gondii and Trypanosoma cruzi.
- Macrophage activation by cord factor (trehalose 6,6'-dimycolate): enhanced association with and intracellular killing of Trypanosoma cruzi.
- Leukotriene B4 Induces Nitric Oxide Synthesis in Trypanosoma cruzi-Infected Murine Macrophages and Mediates Resistance to Infection
- Role of iron in intracellular growth of Trypanosoma cruzi.