Search results for "Nitrite"
showing 10 items of 227 documents
Dihydrocucurbitacin B, isolated from Cayaponia tayuya, reduces damage in adjuvant-induced arthritis
2005
23,24-Dihydrocucurbitacin B, from the anti-rheumatic plant Cayaponia tayuya, was tested on arthritis induced by adjuvant to corroborate the anti-inflammatory properties of this plant. Arthritis was induced in Lewis rats; the resulting arthritic rats were then treated with dihydrocucurbitacin B (1 mg/kg orally, daily, 1 week). The effect of dihydrocucurbitacin B on the synthesis, release, and activity of pro-inflammatory enzymes (elastase, cyclooxygenase-2, and nitric oxide synthase-2) as well as its effect on different mediators (tumor necrosis factor-alpha and interleukin-1beta) were determined. Dihydrocucurbitacin B modified the evolution of the clinical symptoms, reducing the swelling an…
Endothelial nitric oxide synthase in vascular disease: from marvel to menace.
2006
Nitric oxide (NO·) is an important protective molecule in the vasculature, and endothelial NO· synthase (eNOS) is responsible for most of the vascular NO· produced. A functional eNOS oxidizes its substrate l -arginine to l -citrulline and NO·. This normal function of eNOS requires dimerization of the enzyme, the presence of the substrate l -arginine, and the essential cofactor (6 R )-5,6,7,8-tetrahydro- l -biopterin (BH 4 ), one of the most potent naturally occurring reducing agents. Cardiovascular risk factors such as hypertension, hypercholesterolemia, diabetes mellitus, or chronic smoking stimulate the production of reactive oxygen species in the vascular wall. Nicotinamide adenine dinu…
Targeting Heme-Oxidized Soluble Guanylate Cyclase
2007
Increased peripheral vascular resistance is a hallmark of advanced chronic congestive heart failure (CHF) and contributes to the phenomenon of increased afterload that complicates that condition. Multiple factors have been proposed to contribute to this phenomenon, such as increased sodium water content of the vasculature, increased activation of neurohormonal vasoconstrictor forces, and intrinsic abnormalities of the vasculature. During the past decade, it has also been shown that CHF is associated with a severe degree of endothelial dysfunction in experimental animals, as well as in humans. Given that the endothelium, as well as endothelium-dependent vasodilation, plays a crucial role in …
Islet beta-cell apoptosis triggered in vivo by interleukin-1beta is not related to the inducible nitric oxide synthase pathway: evidence for mitochon…
2003
IL-1beta is recognized as an effector cytokine contributing to islet beta-cell destruction during diabetes. We have previously shown in vitro that IL-1beta induces nitric oxide (NO) and beta-cell damage. Here, we show that IL-1beta administration in vivo to Wistar rats transiently increases manganese superoxide dismutase activity, whereas inducible NO synthase is not detected, and the levels of nitrate+nitrate do not change. Moreover, a significant decrease of mitochondrial aconitase, leading to a rise of hydroperoxides, and islet beta-cell apoptosis, involving caspase-3 and -8, is observed. Analysis of adhesion molecules in beta-cells showed that intercellular adhesion molecule-1 is highly…
Dexamethasone suppresses eNOS and CAT-1 and induces oxidative stress in mouse resistance arterioles
2004
Long-term treatment with glucocorticoids is associated with mild to moderate hypertension. We reported previously that downregulation of endothelial NO synthase (eNOS) expression and activity is likely to contribute to this increase in blood pressure. In the present study, we tested the effects of dexamethasone on the vasodilation of microvascular arterioles using implanted dorsal skin-fold chambers in anesthetized C57BL/6J mice. Experiments were performed on control mice or on mice treated with dexamethasone (0.1–3 mg/kg of body wt). Endothelium-dependent vasodilation in response to ACh (0.1–10 μM) was reduced by dexamethasone in a dose-dependent fashion. Comparable inhibition was seen in …
cGMP MODULATES STEM CELLS DIFFERENTIATION TO NEURONS IN BRAIN IN VIVO
2010
During brain development neural stem cells may differentiate to neurons or to other cell types. The aim of this work was to assess the role of cGMP (cyclic GMP) in the modulation of differentiation of neural stem cells to neurons or non-neuronal cells. cGMP in brain of fetuses was reduced to 46% of controls by treating pregnant rats with nitroarginine-methylester (L-NAME) and was restored by co-treatment with sildenafil.Reducing cGMP during brain development leads to reduced differentiation of stem cells to neurons and increased differentiation to non-neuronal cells. The number of neurons in the prefrontal cortex originated from stem cells proliferating on gestational day 14 was 715 +/- 14/…
Exploring Inflammatory Status in Febrile Seizures Associated with Urinary Tract Infections: A Two-Step Cluster Approach
2021
Background: Urinary tract infections (UTIs) are considered common facilitating factors, along with other infections, in triggering febrile seizures (FS). The main purpose of our study was to identify specific inflammatory patterns of UTI cases from other infections in a specific cluster, using a combination of inflammatory biomarkers to differentiate UTIs from other bacterial diseases triggering FS. Method: This prospective study included a number of 136 patients with 197 distinct FS events, from patients hospitalized in the Pediatric Clinical Hospital Sibiu, among which 10.2% were diagnosed with UTIs. Results: In one-third of the patients with UTIs (20 cases), the symptoms were limited to …
Nitrate therapy: new aspects concerning molecular action and tolerance.
2011
Although the short-term vasodilatory properties of organic nitrates are potent and well known, a number of vascular and extravascular changes have been shown to compromise their hemodynamic effects on long-term administration. Among these changes, systemic phenomena such as neurohormonal activation and intravascular volume expansion1 as well as specific vascular changes such as increased vascular superoxide (O2·−) production,2 increased sensitivity to vasoconstrictors,3 and decreased responsiveness to nitric oxide (NO) donors4,5 have long been identified as playing a role. Several hypotheses have been proposed to explain these abnormalities, and over the last 15 years, our groups have focus…
Inhibition of the NF-κB Signaling Pathway Mediates the Anti-inflammatory Effects of Petrosaspongiolide M
2003
Petrosaspongiolide M (PT) is a potent secretory phospholipase A(2) inhibitor and anti-inflammatory agent. This marine metabolite reduced the production of nitrite, prostaglandin E(2), and tumor necrosis factor-alpha in the mouse air pouch injected with zymosan. These effects were also observed in mouse peritoneal macrophages stimulated with zymosan. Inhibition of these inflammatory mediators was related to reductions in inducible nitric oxide synthase, cyclo-oxygenase-2, and tumor necrosis factor-alpha expression. Since nuclear factor-kappaB (NF-kappaB) appears to play a central role in the transcriptional regulation of these proteins by macrophages, we investigated the effects of PT on thi…