Search results for "Nitrites"
showing 5 items of 75 documents
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/…
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…
Nitrate and nitrite in the diet: How to assess their benefit and risk for human health
2015
Nitrate is a natural constituent of the human diet and an approved food additive. It can be partially converted to nitrogen monoxide, which induces vasodilation and thereby decreases blood pressure. This effect is associated with a reduced risk regarding cardiovascular disease, myocardial infarction, and stroke. Moreover, dietary nitrate has been associated with beneficial effects in patients with gastric ulcer, renal failure, or metabolic syndrome. Recent studies indicate that such beneficial health effects due to dietary nitrate may be achievable at intake levels resulting from the daily consumption of nitrate-rich vegetables. N-nitroso compounds are endogenously formed in humans. However…