Spin trapping of vascular nitric oxide using colloid Fe(II)-diethyldithiocarbamate.
Currently available EPR spin-trapping techniques are not sensitive enough for quantification of basal vascular nitric oxide (NO) production from isolated vessels. Here we demonstrate that this goal can be achieved by the use of colloid Fe(DETC)(2). Rabbit aortic or venous strips incubated with 250 microM colloid Fe(DETC)(2) exhibited a linear increase in tissue-associated NO-Fe(DETC)(2) EPR signal during 1 h. Removal of endothelium or addition of 3 mM N(G)-nitro-l-arginine methyl ester (L-NAME) inhibited the signal. The basal NO production was estimated as 5.9 +/- 0.5 and 8.3 +/- 2.1 pmol/min/cm(2) in thoracic aorta and vena cava, respectively. Adding sodium nitrite (10 microM) or xanthine/xanthine oxidase in the incubation medium did not modify the intensity of the basal NO-Fe(DETC)(2) EPR signal. Reducing agents were not required with this method and superoxide dismutase activity was unchanged by the Fe(DETC)(2) complex. We conclude that colloid Fe(DETC)(2) may be a useful tool for direct detection of low amounts of NO in vascular tissue.
Kleschyov
A L
AL
Department of Internal Medicine, University Hospital Eppendorf, Hamburg, Germany.
Mollnau
H
H
Oelze
M
M
Meinertz
T
T
Huang
Y
Y
Harrison
D G
DG
Munzel
T
T
D000818:Animals; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism; D004050:Ditiocarb / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D005296:Ferrous Compounds / Q000378:metabolism / Q000494:pharmacology*; D009569:Nitric Oxide / Q000378:metabolism*; D011817:Rabbits; D013113:Spin Labels; D014680:Veins / Q000187:drug effects* / Q000378:metabolism
D005296:Ferrous Compounds; D013113:Spin Labels; C085124:diethyldithiocarbamate iron(II); D009569:Nitric Oxide; D004050:Ditiocarb