Role of Glutathione Redox State in Oxygen Sensing by Carotid Body Chemoreceptor Cells

This chapter discusses the role of glutathione redox state in oxygen sensing by carotid body (CB) chemoreceptor cells. The basic structural traits of the carotid body CB arterial chemoreceptors are presented to understand the relationship between the arterial blood PO2 and the activation of chemoreceptor cells, which are the O2 sensing structures of the CB. The threshold for the detection of the hypoxic stimulus, and the glutathione system causing modifications in the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio are discussed.The relationship between GSH/GSSG and the oxygen chemoreception is approached from two different points of view. The GSH/ GSSG levels are measured, followed by calculation of the redox environment of the cells and correlation with the activity of chemoreceptor cells in normoxia and in hypoxia. Data is presented on pharmacological manipulation of the redox environment of the cells, as assessed by GSH/GSSG quotients, and possible correlations with the level of activity of chemoreceptor cells. The possible mechanisms of coupling between ROS and the GSH/GSSG system to the cellular effector machineries are also reviewed.