Applicability of new spin trap agent, 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide, in biological system.
Electron spin resonance using spin-trapping is a useful technique for detecting direct reactive oxygen species, such as superoxide (O2.-). However, the widely used spin trap 2,2-dimethyl-3,4-dihydro-2H-pyrrole N-oxide (DMPO) has several fundamental limitations in terms of half-life and stability. Recently, the new spin trap 2-diphenylphosphinoyl-2-methyl-3,4-dihydro-2H-pyrrole N-oxide (DPhPMPO) was developed by us. We evaluated the biological applicability of DPhPMPO to analyze O2.- in both cell-free and cellular systems. DPhPMPO had a larger rate constant for O2.- and formed more stable spin adducts for O2.- than DMPO in the xanthine/xanthine oxidase (X/XO) system. In the phorbol myristate acetate-activated neutrophil system, the detection potential of DPhPMPO for O2.- was significantly higher than that of DMPO (k(DMPO)=13.95M(-1)s(-1), k(DPhPMPO)=42.4M(-1)s(-1)). These results indicated that DPhPMPO is a potentially good candidate for trapping O2.- in a biological system.
Karakawa
Tomohiro
T
Division of Pharmacology and Therapeutics, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, 5-1 Oe-Honmachi, Kumamoto 862-0973, Japan.
Sato
Keizo
K
Muramoto
Yosuke
Y
Mitani
Yoshihiro
Y
Kitamado
Masataka
M
Iwanaga
Tatsuya
T
Nabeshima
Tetsuji
T
Maruyama
Kumiko
K
Nakagawa
Kazuko
K
Ishida
Kazuhiko
K
Sasamoto
Kazumi
K
D002460:Cell Line; D002474:Cell-Free System / Q000737:chemistry; D003497:Cyclic N-Oxides / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D007700:Kinetics; D009504:Neutrophils / Q000737:chemistry / Q000187:drug effects; D011758:Pyrroles / Q000737:chemistry*; D013113:Spin Labels; D019097:Spin Trapping; D013481:Superoxides / Q000032:analysis* / Q000737:chemistry; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D019820:Xanthine / Q000737:chemistry; D014969:Xanthine Oxidase / Q000737:chemistry
C525532:2-(diphenylphosphinoyl)-2-methyl-3,4-dihydro-2H-pyrrole N-oxide; D003497:Cyclic N-Oxides; D011758:Pyrroles; D013113:Spin Labels; D013481:Superoxides; D019820:Xanthine; D014969:Xanthine Oxidase; D013755:Tetradecanoylphorbol Acetate