Superoxide release from interleukin-1B-stimulated human vascular cells: in situ electrochemical measurement.
Release of superoxide anion by cultured vascular cells was investigated with the use of selective microelectrodes. Local concentration of superoxide anion (O2*-) was followed by differential pulse amperometry on a carbon microfiber at 0.1 V/SCE. The oxidation current allows O2*- detection in the 10(-8) M concentration range without interference of the other major oxygen species. Interleukin-1beta-stimulated O2*- release that progressively increased to reach local concentrations at the cell membrane level of 76 +/- 11 nm 40-60 min after stimulation in human cord vein endothelial cells, and 131 +/- 18 nm 1-2 h after stimulation in internal mammary artery smooth muscle cells. In the two types of cells, the O2*- oxidation signal was suppressed in the presence of superoxide dismutase. Spontaneous O2*-release from unstimulated cells was undetectable. These results demonstrate that selective microelectrodes allow direct and real-time monitoring of local O2*- released from vascular endothelial as well as from smooth muscle cells submitted to an inflammatory stimulus.
Privat
C
C
Département de Pharmacologie, UMR 8604, Université René Descartes, Faculté de Médecine Necker, Paris, France. privat@ext.jussieu.fr
Stepien
O
O
David-Dufilho
M
M
Brunet
A
A
Bedioui
F
F
Marche
P
P
Devynck
J
J
Devynck
M A
MA
D002478:Cells, Cultured; D004563:Electrochemistry / Q000379:methods; D004730:Endothelium, Vascular / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000494:pharmacology*; D008839:Microelectrodes; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000032:analysis* / Q000378:metabolism
D007375:Interleukin-1; D013481:Superoxides; D013482:Superoxide Dismutase