Nitric oxide (NO) is an inorganic, gaseous, and reactive free radical that acts as a biologic mediator in processes such as neurotransmission, vasorelaxation, and cytotoxicity. In addition, it has antimicrobial and anti-tumoral activities. NO production is mediated by members of the nitric oxide synthase (NOS) family. The NOS enzyme catalyzes the oxidization of L-arginine into L-citrulline and NO. Several subtypes have been identified: two constitutive isoforms (type I brain/neuronal NOS, and type III endothelial) and one inducible isoform (iNOS, or type II).
iNOS is found in a variety of cell types including macrophages, hepatocytes, synoviocytes, and smooth muscle cells. It is induced by a combination of lipopolysaccharide and certain cytokines (IFN-gamma, TNF, IL-1, IL-2, and LPS). After cytokine induction, iNOS exhibits a delayed activity response which is then followed by a significant increase in NO production over a long period of time. Bredt's group at Johns Hopkins published the original isolation and characterization of iNOS in Nature by using an iNOS antibody1. Xu’s group used an iNOS antibody to identify a cardiac form of iNOS in the sarcoplasmic reticulum that responds to calcium and modulates ion active transport2. Additionally, an iNOS antibody was employed in immunoblotting and immunohistochemistry studies on pulmonary circulation3. The data from this study identifies LPS-induced differential iNOS expression as the antagonist in sepsis and endotoxemia-induced systemic hypotension and pulmonary hypertension. Han’s group used the iNOS antibody for in their hypoxia studies in smooth muscle and the deep femoral artery4. Very recent translational research studies with the iNOS antibody investigated the role of LPS and IL-1 in astrocytes, and provide valuable insight into neuroinflammation and both autocrine and paracrine activation in the CNS5.
Novus Biologicals offers iNOS reagents for your research needs including:
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