RT info:eu-repo/semantics/article T1 Significance of ROS in oxygen sensing in cell systems with sensitivy to ohysiological hypoxia A1 González, Constancio A1 Sanz Alfayate, Gloria A1 Agapito Serrano, María Teresa A1 Gómez Niño, María Ángeles A1 Rocher Martín, María Asunción A1 Obeso Cáceres, Ana María de la Luz K1 Neurofisiología AB Reactive oxygen species (ROS) are oxygen-containing molecular entities which are more potent and effectiveoxidizing agents than is molecular oxygen itself. With the exception of phagocytic cells, where ROS play an importantphysiological role in defense reactions, ROS have classically been considered undesirable byproducts of cellmetabolism, existing several cellular mechanisms aimed to dispose them. Recently, however, ROS have beenconsidered important intracellular signaling molecules, which may act as mediators or second messengers in many cellfunctions. This is the proposed role for ROS in oxygen sensing in systems, such as carotid body chemoreceptor cells,pulmonary artery smooth muscle cells, and erythropoietin-producing cells. These unique cells comprise essential partsof homeostatic loops directed to maintain oxygen levels in multicellular organisms in situations of hypoxia. Thepresent article examines the possible significance of ROS in these three cell systems, and proposes a set of criteria thatROS should satisfy for their consideration as mediators in hypoxic transduction cascades. In none of the three celltypes do ROS satisfy these criteria, and thus it appears that alternative mechanisms are responsible for thetransduction cascades linking hypoxia to the release of neurotransmitters in chemoreceptor cells, contraction inpulmonary artery smooth muscle cells and erythropoietin secretion in erythropoietin producing cells. PB Elsevier SN 1569-9048 YR 2002 FD 2002 LK http://uvadoc.uva.es/handle/10324/7168 UL http://uvadoc.uva.es/handle/10324/7168 LA eng NO Respiratory Physiology & Neurobiology 132 (2002) 17–41 DS UVaDOC RD 21-nov-2024