Biomaterial Database

In vivo free radical generation by chromium(VI): an electron spin resonance spin-trapping investigation. 1994

M B Kadiiska, and Q H Xiang, and R P Mason

Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709.

Although studies in chemical and biological systems have demonstrated that free radical formation is mediated by Cr(VI), no ESR evidence for the generation of free radicals in vivo has been reported. We have employed an ESR spin-trapping technique to detect an adduct of the spin trap alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone (4-POBN) in the bile of animals given an intragastric dose of potassium dichromate. In this study, we provide evidence for in vivo radical generation resulting from Cr(VI)-poisoned rats. Upon the administration of Cr(VI) and 4-POBN, the ESR spectrum of the radical adducts present in the bile exhibited hyperfine coupling constants aN = 15.71 G and a beta H = 2.90 G. We suggest that the radical responsible for this 4-POBN adduct is carbon-centered and derived from endogenous lipids. The radical adducts detected in the bile from Cr(VI)-treated rats are proposed to be formed and trapped in the liver and excreted into bile. This is the first report of electron spin resonance evidence for the in vivo generation of free radicals by Cr(VI).

UI	MeSH Term	Description	Entries
D007770	L-Lactate Dehydrogenase	A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.	Lactate Dehydrogenase,Dehydrogenase, L-Lactate,Dehydrogenase, Lactate,L Lactate Dehydrogenase
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008297	Male		Males
D009589	Nitrogen Oxides	Inorganic oxides that contain nitrogen.	Nitrogen Oxide,Oxide, Nitrogen,Oxides, Nitrogen
D011192	Potassium Dichromate	Chromic acid (H2Cr2O7), dipotassium salt. A compound having bright orange-red crystals and used in dyeing, staining, tanning leather, as bleach, oxidizer, depolarizer for dry cells, etc. Medically it has been used externally as an astringent, antiseptic, and caustic. When taken internally, it is a corrosive poison.	Potassium Bichromate,K2Cr2O7,Bichromate, Potassium,Dichromate, Potassium
D011725	Pyridines	Compounds with a six membered aromatic ring containing NITROGEN. The saturated version is PIPERIDINES.
D004578	Electron Spin Resonance Spectroscopy	A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.	ENDOR,Electron Nuclear Double Resonance,Electron Paramagnetic Resonance,Paramagnetic Resonance,Electron Spin Resonance,Paramagnetic Resonance, Electron,Resonance, Electron Paramagnetic,Resonance, Electron Spin,Resonance, Paramagnetic
D005609	Free Radicals	Highly reactive molecules with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. Free radicals include reactive oxygen and nitrogen species (RONS). They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.	Free Radical
D000410	Alanine Transaminase	An enzyme that catalyzes the conversion of L-alanine and 2-oxoglutarate to pyruvate and L-glutamate. (From Enzyme Nomenclature, 1992) EC 2.6.1.2.	Alanine Aminotransferase,Glutamic-Pyruvic Transaminase,SGPT,Alanine-2-Oxoglutarate Aminotransferase,Glutamic-Alanine Transaminase,Alanine 2 Oxoglutarate Aminotransferase,Aminotransferase, Alanine,Aminotransferase, Alanine-2-Oxoglutarate,Glutamic Alanine Transaminase,Glutamic Pyruvic Transaminase,Transaminase, Alanine,Transaminase, Glutamic-Alanine,Transaminase, Glutamic-Pyruvic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia