Ozone exposure generates free radicals in the blood samples in vitro. Detection by the ESR spin-trapping technique.
Generation of free radicals in the reaction of ozone with blood samples and related salt solutions was investigated in vitro by using ESR spin-trapping technique with DMPO. In the reactions of low levels of ozone, a carbon-centered radical was spin-trapped with DMPO, giving rise to the 6-line ESR signal in both whole blood and blood plasma. In the blood plasma, DMPO-spin adduct of hydroxyl radical (DMPO-OH) was detected together with the spin adduct of carbon-centered radical. The present spin-trapping study demonstrates that, when exposed to ozone, 0.9% NaCl solution in the presence of DMPO gives rise to the formation of DMPO-OH. The addition effects of ethanol, which is a .OH scavenger, into the NaCl solution reveal that DMPO-OH is produced by the reaction of DMPO with both .OH and unidentified oxidants originated from the reaction of Cl- and ozone. Based on these observations, we consider that .OH is generated similarly in the blood plasma exposed to ozone. The ESR study of DMPO-spin adducts in the ozone-exposed aqueous solution of NaOCl indicates that Cl- reacts with ozone to give ClO-. Presumably, further oxidation of ClO- by ozone leads to the formations of .OH and the unidentified oxidants.
Ueno
I
I
The Institute of Physical and Chemical Research, Saitama, Japan.
Hoshino
M
M
Miura
T
T
Shinriki
N
N
D001769:Blood / Q000187:drug effects*; D002712:Chlorides / Q000737:chemistry; D003497:Cyclic N-Oxides; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals / Q000097:blood; D017665:Hydroxyl Radical / Q000097:blood; D010126:Ozone / Q000737:chemistry / Q000494:pharmacology*; D012965:Sodium Chloride / Q000737:chemistry; D012996:Solutions; D013113:Spin Labels
D002712:Chlorides; D003497:Cyclic N-Oxides; D005609:Free Radicals; D012996:Solutions; D013113:Spin Labels; D017665:Hydroxyl Radical; D012965:Sodium Chloride; D010126:Ozone; C017245:5,5-dimethyl-1-pyrroline-1-oxide