Characterization of Redox Activity in Resting and Activated Mast Cells by Reduction and Reoxidation of Lipophilic Nitroxides

Suzuki-Nishimura, Tamiko; Swartz, Harold M.

doi:10.1016/s0306-3623(98)00066-4

Cited by 5 publications

(3 citation statements)

References 26 publications

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“…One example is change in redox balance that might effect the activity of the cells. Another interesting finding is that mast cell degranulation appears not be affected by redox changes induced by hypoxia [26]. However, the effect on cytokine synthesis and secretion has not been studied.…”

Section: Discussionmentioning

confidence: 99%

Mast Cell Survival and Mediator Secretion in Response to Hypoxia

et al. 2010

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Tissue hypoxia is a consequence of decreased oxygen levels in different inflammatory conditions, many associated with mast cell activation. However, the effect of hypoxia on mast cell functions is not well established. Here, we have investigated the effect of hypoxia per se on human mast cell survival, mediator secretion, and reactivity. Human cord blood derived mast cells were subjected to three different culturing conditions: culture and stimulation in normoxia (21% O2); culture and stimulation in hypoxia (1% O2); or 24 hour culture in hypoxia followed by stimulation in normoxia. Hypoxia, per se, did not induce mast cell degranulation, but we observed an increased secretion of IL-6, where autocrine produced IL-6 promoted mast cell survival. Hypoxia did not have any effect on A23187 induced degranulation or secretion of cytokines. In contrast, cytokine secretion after LPS or CD30 treatment was attenuated, but not inhibited, in hypoxia compared to normoxia. Our data suggests that mast cell survival, degranulation and cytokine release are sustained under hypoxia. This may be of importance for host defence where mast cells in a hypoxic tissue can react to intruders, but also in chronic inflammations where mast cell reactivity is not inhibited by the inflammatory associated hypoxia.

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Section: Discussionmentioning

confidence: 99%

Mast Cell Survival and Mediator Secretion in Response to Hypoxia

et al. 2010

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“…Increased concentrations of oxygen within cells usually lower the reduction rates by changing the redox states of mitochondrial enzymes involved. The extent of this effect varies depending on both the cell type and the lipophilicity of the nitroxide [24] , [62] , [65] , [68] , [69] . The rate of reduction of lipophilic nitroxides # 17 and # 18 in the doxyl stearate series is especially sensitive to severe hypoxia (intracellular [O 2 ]<1 μM) [62] , [68] , [69] .…”

Section: Biochemistry Of Nitroxidesmentioning

confidence: 99%

“…The extent of this effect varies depending on both the cell type and the lipophilicity of the nitroxide [24] , [62] , [65] , [68] , [69] . The rate of reduction of lipophilic nitroxides # 17 and # 18 in the doxyl stearate series is especially sensitive to severe hypoxia (intracellular [O 2 ]<1 μM) [62] , [68] , [69] . In the presence of oxygen, oxidation back to the nitroxide of the lipid soluble hydroxylamines occurs in membranes at the level of cytochrome c oxidase and competes with the reduction of nitroxides at a rate that increases with oxygen concentration [70] .…”

Section: Biochemistry Of Nitroxidesmentioning

confidence: 99%

In vivo evaluation of different alterations of redox status by studying pharmacokinetics of nitroxides using magnetic resonance techniques

2016

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Free radicals, particularly reactive oxygen species (ROS), are involved in various pathologies, injuries related to radiation, ischemia-reperfusion or ageing. Unfortunately, it is virtually impossible to directly detect free radicals in vivo, but the redox status of the whole organism or particular organ can be studied in vivo by using magnetic resonance techniques (EPR and MRI) and paramagnetic stable free radicals – nitroxides. Here we review results obtained in vivo following the pharmacokinetics of nitroxides on experimental animals (and a few in humans) under various conditions. The focus was on conditions where the redox status has been altered by induced diseases or harmful agents, clearly demonstrating that various EPR/MRI/nitroxide combinations can reliably detect metabolically induced changes in the redox status of organs. These findings can improve our understanding of oxidative stress and provide a basis for studying the effectiveness of interventions aimed to modulate oxidative stress. Also, we anticipate that the in vivo EPR/MRI approach in studying the redox status can play a vital role in the clinical management of various pathologies in the years to come providing the development of adequate equipment and probes.

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EPR Spectroscopy of Function In Vivo

Swartz

Khan

Biomedical EPR, Part A: Free Radicals, Metals, Medicine, and Physiology

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Characterization of Redox Activity in Resting and Activated Mast Cells by Reduction and Reoxidation of Lipophilic Nitroxides

Cited by 5 publications

References 26 publications

Mast Cell Survival and Mediator Secretion in Response to Hypoxia

Mast Cell Survival and Mediator Secretion in Response to Hypoxia

In vivo evaluation of different alterations of redox status by studying pharmacokinetics of nitroxides using magnetic resonance techniques

EPR Spectroscopy of Function In Vivo

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