Extra- and intracellular free iron and the carotid body responses.
The hypothesis that chelation of free iron, by decreasing reactive oxygen species (ROS), might mimic hypoxia and stimulate the carotid body was tested. We used the iron chelators, desferrioxamine (DFO, 200-400 microM) initially, and later ciclopirox olamine (CPX, 2.5-5.0 microM), on rat carotid body in vitro and measured chemosensory activity and [Ca2+]i in isolated cultured glomus cell clusters during normoxia and hypoxia. Although acute treatment of DFO might not penetrate the cell, and extracellular DFO would not influence these activities whereas CPX significantly increased chemosensory activities as well as increased [Ca2+]i in normoxia. We concluded that chelation of extracellular free iron did not alter ROS formation and oxygen sensing. Chelation of intracellular free iron and, therefore, a decrease in intracellular ROS appears to influence oxygen sensing in the carotid body.
Daudu
Peter A
PA
Department of Physiology, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6085, USA.
Roy
Arijit
A
Rozanov
Charmaine
C
Mokashi
Anil
A
Lahiri
Sukhamay
S
D000818:Animals; D002344:Carotid Body / Q000187:drug effects / Q000502:physiology*; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005110:Extracellular Space / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000187:drug effects / Q000502:physiology*; D007501:Iron / Q000502:physiology*; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism
D002614:Chelating Agents; D017382:Reactive Oxygen Species; D007501:Iron