TY - JOUR
T1 - Application of spin traps to biological systems
AU - Rosen, Gerald M.
AU - Cohen, Myron S.
AU - Britigan, Bradley E.
AU - Pou, Sovitj
N1 - Funding Information:
This work was supported in part by grants from the National Science Foundation, The Chemistry of Life Processes Program, DCB 86161 15; National Institutes of Health, HL 33550 and A1 23939; The Council for Tobacco Research-U.S.A.. Inc.; Veterans Administration Research Service; The Pfizer Scholars Program, and the Cystic Fibrosis Foundation. B.E.B. is a Veterans Administration Research Associate Career Development Awardee.
PY - 1990
Y1 - 1990
N2 - Since 1971. when nitroxides were first reported to be bioreduced, several cellular enzymes, in addition to ascorbic acid. have been found to catalyze the reduction of nitroxides to their corresponding hydroxylami-nes. Numerous studies have demonstrated that cellular bioreduction of nitroxides are both dependent upon the structure of the nitroxide and cell type. For example, pyrrolidinyloxyls are considerably more resistant to bioreduction than their corresponding piperidinyloxyls. In addition, cellular levels of reductases present in freshly isolated rat hepatocytes are considerably greater than concentrations found in freshly isolated rat enterocytes. Thus, through the proper selection of a cell type and an appropriate nitroxide. one can study cellular-mediated free radical processes. With the discovery that αhydrogen-containing nitroxides, including 2, Z-dimethyl-S-hydroxy-l-pyrrolidinyloxyl (DMPO-OH) decompose rapidly in the presence of superoxide and thiols, the ability to determine if hydroxyl radical is generated during stimulation of human neutrophils, is in doubt. To explore the limits of spin trapping in this context. we have studied the effect of varying the rates of superoxide production. in the presence and absence of thiols, on the decomposition of DMPO-OH. In parallel studies, we have found that t-butyl αmethyl-4-pyridinyl-N-oxide nitroxide (4-POBN-CH3) will not degrade in the presence of superoxide and a thiol. From these studies. we have determined that if hydroxyl radicals were generated as an isolated event in the presence of a continual flow of superoxide. spin trapping might not be able to detect its formation. Otherwise. spin trapping should be able to measure hydroxyl radicals. if continually generated, during activation of human neutrophils.
AB - Since 1971. when nitroxides were first reported to be bioreduced, several cellular enzymes, in addition to ascorbic acid. have been found to catalyze the reduction of nitroxides to their corresponding hydroxylami-nes. Numerous studies have demonstrated that cellular bioreduction of nitroxides are both dependent upon the structure of the nitroxide and cell type. For example, pyrrolidinyloxyls are considerably more resistant to bioreduction than their corresponding piperidinyloxyls. In addition, cellular levels of reductases present in freshly isolated rat hepatocytes are considerably greater than concentrations found in freshly isolated rat enterocytes. Thus, through the proper selection of a cell type and an appropriate nitroxide. one can study cellular-mediated free radical processes. With the discovery that αhydrogen-containing nitroxides, including 2, Z-dimethyl-S-hydroxy-l-pyrrolidinyloxyl (DMPO-OH) decompose rapidly in the presence of superoxide and thiols, the ability to determine if hydroxyl radical is generated during stimulation of human neutrophils, is in doubt. To explore the limits of spin trapping in this context. we have studied the effect of varying the rates of superoxide production. in the presence and absence of thiols, on the decomposition of DMPO-OH. In parallel studies, we have found that t-butyl αmethyl-4-pyridinyl-N-oxide nitroxide (4-POBN-CH3) will not degrade in the presence of superoxide and a thiol. From these studies. we have determined that if hydroxyl radicals were generated as an isolated event in the presence of a continual flow of superoxide. spin trapping might not be able to detect its formation. Otherwise. spin trapping should be able to measure hydroxyl radicals. if continually generated, during activation of human neutrophils.
KW - Ascorbate
KW - DMPO
KW - Nitroxides
KW - Spin trapping
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U2 - 10.3109/10715769009145676
DO - 10.3109/10715769009145676
M3 - Article
C2 - 2167256
AN - SCOPUS:0025132309
SN - 1071-5762
VL - 9
SP - 187
EP - 195
JO - Free Radical Research
JF - Free Radical Research
IS - 3-6
ER -