Effects of reducing agents on glutathione metabolism and the function of carotid body chemoreceptor cells
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C. Gonzalez
Abstract
Two current hypotheses of O2 sensing in the carotid body (CB) chemoreceptors suggest participation of oxygen reactive (ROS) species, but they are mechanistically opposed. One postulates that hypoxia decreases ROS levels; the other that hypoxia increases them. Yet, both propose that the ensuing alteration in the cellular redox environment is the key signal triggering hypoxic chemoreception. Since the glutathione redox pair is the main cellular buffer for ROS and the main determinant of the general redox environment of the cells, a way to test whether ROS participate in chemoreception is to determine glutathione levels and to correlate them with the activity of CB chemoreceptor cells. We found that hypoxia does not alter the glutathione reduction potential but that it activates chemoreceptor cell neurosecretion. Incubation of tissues with reduced glutathione increases the glutathione-reducing potential but does not activate chemoreceptor cells in normoxia nor does it modify hypoxic activation. Like reduced glutathione, N-acetylcysteine promoted a general reducing environment in the cells without alteration of chemoreceptor cell activity. N-(mercaptopropionyl)-glycine, like the two previous agents, increases the reduction potential of glutathione. In contrast, the compound activated chemoreceptor cells in normoxia, promoting a dose- and Ca2+-dependent neurosecretion and a potentiation of the hypoxic responses. The existence of multiple relationships between glutathione reduction potential in the cells and their activity indicates that the general cellular redox environment is not a factor determining chemoreceptor cell activation. It cannot be excluded that the local redox environments of restricted microdomain(s) in the cells with specific regulating mechanisms are important signals for chemoreceptor cell activity.
Copyright © 2004 by Walter de Gruyter GmbH & Co. KG
Articles in the same Issue
- Oxygen and the Cell
- O2 sensing in the human ductus arteriosus: redox-sensitive K+ channels are regulated by mitochondria-derived hydrogen peroxide
- Oxidative stress in the systemic and cellular responses to intermittent hypoxia
- HIF hydroxylation and cellular oxygen sensing
- Visualization of the three-dimensional organization of hypoxia-inducible factor-1α and interacting cofactors in subnuclear structures
- Modulation of glucokinase expression by hypoxia-inducible factor 1 and upstream stimulatory factor 2 in primary rat hepatocytes
- Redox-sensitive regulation of the HIF pathway under non-hypoxic conditions in pulmonary artery smooth muscle cells
- Measurement of exhaled hydrogen peroxide from rabbit lungs
- Effects of reducing agents on glutathione metabolism and the function of carotid body chemoreceptor cells
- Expression of functional purinergic receptors in pulmonary neuroepithelial bodies and their role in hypoxia chemotransmission
- Remodelling of Ca2+ homeostasis in type I cortical astrocytes by hypoxia: evidence for association with Alzheimer's disease
- Simultaneous exposure of rats to dioxin and carbon monoxide reduces the xenobiotic but not the hypoxic response
- Structure and expression of two kininogen genes in mice
- The central domain of the matrix protein of HIV-1: influence on protein structure and virus infectivity
- Skin secretion of the toad Bombina variegata contains multiple insulin-releasing peptides including bombesin and entirely novel insulinotropic structures
- Inhibition of lentil copper/TPQ amine oxidase by the mechanism-based inhibitor derived from tyramine
- Enhanced expression of basolateral multidrug resistance protein isoforms Mrp3 and Mrp5 in rat liver by LPS
- Critical O2 and NO concentrations in NO-induced cell death in a rat liver sinusoidal endothelial cell line
Articles in the same Issue
- Oxygen and the Cell
- O2 sensing in the human ductus arteriosus: redox-sensitive K+ channels are regulated by mitochondria-derived hydrogen peroxide
- Oxidative stress in the systemic and cellular responses to intermittent hypoxia
- HIF hydroxylation and cellular oxygen sensing
- Visualization of the three-dimensional organization of hypoxia-inducible factor-1α and interacting cofactors in subnuclear structures
- Modulation of glucokinase expression by hypoxia-inducible factor 1 and upstream stimulatory factor 2 in primary rat hepatocytes
- Redox-sensitive regulation of the HIF pathway under non-hypoxic conditions in pulmonary artery smooth muscle cells
- Measurement of exhaled hydrogen peroxide from rabbit lungs
- Effects of reducing agents on glutathione metabolism and the function of carotid body chemoreceptor cells
- Expression of functional purinergic receptors in pulmonary neuroepithelial bodies and their role in hypoxia chemotransmission
- Remodelling of Ca2+ homeostasis in type I cortical astrocytes by hypoxia: evidence for association with Alzheimer's disease
- Simultaneous exposure of rats to dioxin and carbon monoxide reduces the xenobiotic but not the hypoxic response
- Structure and expression of two kininogen genes in mice
- The central domain of the matrix protein of HIV-1: influence on protein structure and virus infectivity
- Skin secretion of the toad Bombina variegata contains multiple insulin-releasing peptides including bombesin and entirely novel insulinotropic structures
- Inhibition of lentil copper/TPQ amine oxidase by the mechanism-based inhibitor derived from tyramine
- Enhanced expression of basolateral multidrug resistance protein isoforms Mrp3 and Mrp5 in rat liver by LPS
- Critical O2 and NO concentrations in NO-induced cell death in a rat liver sinusoidal endothelial cell line
