Search results for "OXIDASE"
showing 10 items of 927 documents
Molecular Mechanisms of the Crosstalk Between Mitochondria and NADPH Oxidase Through Reactive Oxygen Species—Studies in White Blood Cells and in Anim…
2014
Aims: Oxidative stress is involved in the development of cardiovascular disease. There is a growing body of evidence for a crosstalk between different enzymatic sources of oxidative stress. With the present study, we sought to determine the underlying crosstalk mechanisms, the role of the mitochondrial permeability transition pore (mPTP), and its link to endothelial dysfunction. Results: NADPH oxidase (Nox) activation (oxidative burst and translocation of cytosolic Nox subunits) was observed in response to mitochondrial reactive oxygen species (mtROS) formation in human leukocytes. In vitro, mtROS-induced Nox activation was prevented by inhibitors of the mPTP, protein kinase C, tyrosine kin…
Reactive oxygen and ethylene are involved in the regulation of regurgitant-induced responses in bean plants.
2004
Summary Application of regurgitant from Leptinotarsa decemlineata Say on wound surfaces of one wounded leaf of intact bean ( Phaseolus vulgaris L.) plants resulted in activation of ethylene biosynthesis followed by an increase of both peroxidase and polyphenol oxidase activity. The aim of the present investigation was to study the source of increased oxidative enzyme activities in regurgitant-treated bean leaves and to determine if hydrogen peroxide and ethylene biosynthesis is responsible for regurgitant-induced amplification of wound responses in bean plants. As the regurgitant contained relative high activities of both peroxidase and polyphenol oxidase, there is a possibility that increa…
Humoral responses during wound healing in Holothuria tubulosa (Gmelin, 1788)
2021
Abstract Wounds in living organisms trigger tissue-repair mechanisms. The sea cucumber (Holoturia tubulosa) is an excellent model species for achieving a better understanding of the humoral and cellular aspects involved in such healing processes. Consequently, this study assesses data on its morphometric, physiological and humoral responses 1, 2, 6, 24 and 48h after wound induction. In particular, morphometric data on the weight, width, length and coelomic-fluid volume of the species were estimated at different times during our experiments. In addition, the humoral aspects related to the enzymatic activity of esterase, alkaline phosphatase and peroxidase, as well as the cytotoxic activity o…
Association of Exposure to Ambient Air Pollution With Thyroid Function During Pregnancy
2019
Key Points Question Is exposure to ambient air pollution in the first trimester associated with thyroid function throughout pregnancy? Findings Among 9931 pregnant women in 4 European cohorts and 1 US cohort, an increase of 5 μg/m3 in exposure to particulate matter with an aerodynamic diameter of 2.5 μm or less was associated with 20% higher odds of hypothyroxinemia. Meaning The findings of this study raise the possibility that exposure to particulate matter might disrupt thyroid function in pregnant women.
Explaining the phenomenon of nitrate tolerance.
2005
During the last century, nitroglycerin has been the most commonly used antiischemic and antianginal agent. Unfortunately, after continuous application, its therapeutic efficacy rapidly vanishes. Neurohormonal activation of vasoconstrictor signals and intravascular volume expansion constitute early counter-regulatory responses (pseudotolerance), whereas long-term treatment induces intrinsic vascular changes, eg, a loss of nitrovasodilator-responsiveness (vascular tolerance). This is caused by increased vascular superoxide production and a supersensitivity to vasoconstrictors secondary to a tonic activation of protein kinase C. NADPH oxidase(s) and uncoupled endothelial nitric oxide synthase …
Regulation of NADPH oxidase-mediated superoxide production by acetylation and deacetylation
2021
Oral treatment of apolipoprotein E-knockout (ApoE-KO) mice with the putative sirtuin 1 (SIRT1) activator resveratrol led to a reduction of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity in the heart. In contrast, the SIRT1 inhibitor EX527 enhanced the superoxide production in isolated human polymorphonuclear granulocytes. In human monocytic THP-1 cells, phorbol ester-stimulated superoxide production was enhanced by inhibitors of histone deacetylases (HDACs; including quisinostat, trichostatin A (TSA), PCI34051, and tubastatin A) and decreased by inhibitors of histone acetyltransferases [such as garcinol, curcumin, and histone acetyltransferase (HAT) Inhibitor II]. Thes…
Protective effect of apocynin in a mouse model of chemically-induced colitis.
2013
Apocynin, a constituent of Picrorhiza kurroa, successfully inhibits NADPH oxidase and shows promise as an anti-inflammatory drug. Now, we report anti-inflammatory effects of apocynin in an experimental colitis model induced by dextran sulfate sodium as well as the effects on the mediators involved in this process. Apocynin reduced the colitis induced in mice by administration of 5 % dextran sulfate sodium during 7 days. Mice were fed a control diet or a diet supplemented with 2 % of apocynin or 2 % of rutin. Sulfasalazine (50 mg/kg, p. o.) was used as a positive control. Treatment with apocynin and rutin ameliorated the course of colonic inflammation with results similar to those of the ref…
Origin of the natural variation in the storage of dietary carotenoids in freshwater amphipod crustaceans
2020
16 pages; International audience; Carotenoids are diverse lipophilic natural pigments which are stored in variable amounts by animals. Given the multiple biological functions of carotenoids, such variation may have strong implications in evolutionary biology. Crustaceans such as Gammarus amphipods store large amounts of these pigments and inter-population variation occurs. While differences in parasite selective pressure have been proposed to explain this variation, the contribution of other factors such as genetic differences in the gammarid ability to assimilate and/or store pigments, and the environmental availability of carotenoids cannot be dismissed. This study investigates the relati…
Extensive sampling sheds light on species-level diversity in Palearctic Placobdella (Annelida: Clitellata: Glossiphoniiformes)
2022
The bloodfeeding leech genus Placobdella is dominated by North American diversity, with only a single nominal species known from Central America and one from the Palearctic region. This is likely due to considerable underestimation of Palearctic biodiversity, but investigations into potential hidden diversity are lacking. To shed light on this, the present study introduces new data for specimens initially identified as Placobdella costata from Ukraine (close to the type locality), Italy, Germany, Latvia, Montenegro, Bulgaria, Slovenia, Turkey, Azerbaijan, Tunisia, and Algeria, and uses both nuclear (Internal Transcribed Spacer [ITS] region) and mitochondrial (cytochrome c oxidase subunit I …
A molecular study of Neophyllaphis varicolor (Hemiptera, Aphididae) in Costa Rica
2019
The genus Neophyllaphis (Takahashi) (Aphididae: Neophyllaphidinae) is composed of 18 species; however, in the Americas only nine species have been reported previously. A new species, Neophyllaphis varicolor Miller & Halbert, was described in 2014 in USA. Colonies resembling those of this new species have been observed in Costa Rica on Podocarpus spp. In order to determine if N. varicolor is also present in Costa Rica, we sampled Neophyllaphis colonies from Podocarpus falcatus and P. chinensis. Additionally, we sampled individuals from Podocarpus sp. in Spain and Vietnam. DNA of each sample was extracted and used to amplify and sequence the cytochrome c oxidase subunit I (COI) and elongation…