Arginine is a common substrate for both inducible nitric oxide synthase (iNOS) and arginase. The competition between iNOS and arginase for arginine contributes to the outcome of several parasitic and bacterial infections. Salmonella infection in macrophage cell line RAW264.7 induces iNOS. Because the availability of l-arginine is a major determinant for nitric oxide (NO) synthesis, we hypothesi...

Nitric oxide (NO) is involved in the pathogenesis of acute and chronic inflammatory conditions, namely in allergic contact dermatitis (ACD). However, the mechanism by which NO acts in ACD remains elusive. The present study focuses on the effects of different contact sensitizers (2,4-dinitrofluorbenzene, 1,4-phenylenediamine, nickel sulfate), the inactive analogue of DNFB, 2,4-dichloronitrobenze...

The antihistoplasma activity of recombinant murine gamma interferon (rMuIFN-gamma)-treated macrophages of the RAW 264.7 cell line depends on the generation of nitric oxide (NO.) from L-arginine. Macrophages of the P388D1 cell line treated with rMuIFN-gamma do not produce NO. or inhibit the intracellular growth of Histoplasma capsulatum. NO. is generated by the inducible enzyme nitric oxide synt...

For centuries, Aloe has been used as a herbal plant remedy against skin disorders, diabetes, and for its cardiac stimulatory activity. Here, we examined the gastroprotective effects of an Aloe vera polymer fraction (Avpf; molecular weight cut-off ≥50 kDa; 150 mg/kg body weight, p.o.) on an ethanol-induced gastric lesion mouse model. Mice pre-treated with Avpf had significantly fewer gastric les...

We sought to establish a model of inflammatory bowel disease by augmenting the activity of the local immune system with Freund's complete adjuvant, and to determine if inducible nitric oxide synthase (iNOS) expression and peroxynitrite formation accompanied the inflammatory condition. In anaesthetized guinea-pigs, a loop of distal ileum received intraluminal 50% ethanol followed by Freund's com...

OBJECTIVE Inducible nitric oxide synthase (iNOS) is expressed in arteries during inflammation and may contribute to vascular dysfunction. Effects of gene transfer of iNOS to carotid arteries were examined in vitro in the absence of systemic inflammation to allow examination of mechanisms by which iNOS impairs contraction and relaxation. METHODS AND RESULTS After gene transfer of iNOS with an ...

Nitric oxide (NO) has been implicated in many cellular processes. We examined the temporal and spatial expressions of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in mouse uteri during the estrous cycle and early pregnancy, as well as the regulation of eNOS and iNOS by estradiol (E2) and progesterone (P4) in ovariectomized mouse uteri using in situ hybridi...

Nitric oxide synthases (NOSs, EC 1.14.13.39) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule that helps to modulate the vascular tone, insulin secretion, airway tone and peristalsis, etc, and NO is involved in angiogenesis and neural development. It may function as a retrograde neurotransmitter. NO is mediate...

OBJECTIVE Previous studies provided evidence that many factors contribute to retinal angiogenesis, including inducible nitric oxide synthase (iNOS), hypoxia-inducible factor-1 alpha (HIF-1 alpha) and vascular endothelial growth factor (VEGF). But the role of nitric oxide generated by iNOS in the regulation of expression of hypoxia-inducible genes in retinopathy of prematurity remains unclear. S...

Respiratory epithelial cells are actively involved in the host defence and inflammatory reactions of the airways. Nuclear factor-kappaB (NF-kappaB) is a transcription factor that plays a pivotal role in many cellular responses to environmental changes. The inducible nitric oxide synthase (iNOS) isoform has been implicated in airway inflammation as well as in normal airway function. In this stud...