We have focused on the role of oxidative mechanisms in ischemia/reperfusion induced brain damage in the Mongolian gerbil model. We have found that: A) In vivo salicylate hydroxylation is increased implicating an increased flux of hydroxyl free radicals, B) In vivo spin-trapping techniques show formation of spin-trapped free radicals, C) Certain spin-traps (PBN, alpha- phenyl-t-butyl nitrone) administered to gerbils offer protection, D) Lesioned brain tissue homogenate is more prone to peroxidation and E) Proteins are oxidatively damaged in lesioned brain. Other related leads we have recently made indicate: A) Oxidative damage to RNA and DNA in peroxidized brain, B) Mediated loss of enzymes which may be responsible for the build up of the excitatory toxic amino acid glutamate in lesioned brain, C) An enhanced expression of specific genes in lesioned brains, and D) Older gerbils have an increased susceptibility to ischemia/reperfusion injury. Focus will be directed toward investigating the mechanism of action of spin-traps in the context of rigorously assessing brain regional localization of oxidative damage to nuclei acids and proteins and on the time-course and the nature of the free radicals produced in the ischemia/reperfusion insult (IRI)-lesioned gerbil brain. We will use the Mongolian gerbil brain ischemia/reperfusion model and: A) Determine using spin-trapping techniques combined with HLPC and mass spectroscopy the nature of the spin-trapped free radicals produced in lesioned brain. A novel approach of utilizing a combination of alpha-carbon isotopes of the spin-trap PBN (alpha-12CPBN, alpha-13CPBN) administered at specific time points in the development of the IRI-induced injury will be used to determine the time-course of the free radicals produced. B) Determine if oxygen free radical damage to RNA and DNA, namely the presence of increased levels of 8-hydroxyguanosine (8-OHG) and 8-hydroxydeoxyguanosine (8-OHdG), respectively, are formed in lesioned brains. C) Determine the extent of oxidative damage to proteins and characterize the regional localization and time-course of oxidative damage. D) 31P-NMR in vivo spectroscopy will be used to standardize the extent of cortical ischemia for subsequent determination of oxidative damage to brain tissue.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS023307-06
Application #
3406603
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1986-09-01
Project End
1994-07-31
Budget Start
1993-08-01
Budget End
1994-07-31
Support Year
6
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Oklahoma Medical Research Foundation
Department
Type
DUNS #
937727907
City
Oklahoma City
State
OK
Country
United States
Zip Code
73104
Floyd, Robert A (2009) Serendipitous findings while researching oxygen free radicals. Free Radic Biol Med 46:1004-13
Carney, J M; Hall, N C; Cheng, M et al. (1996) Protein and lipid oxidation following ischemia/reperfusion injury, the role of polyamines: an electron paramagnetic resonance analysis. Adv Neurol 71:259-68;discussion 268-9
Tabatabaie, T; Floyd, R A (1996) Inactivation of glutathione peroxidase by benzaldehyde. Toxicol Appl Pharmacol 141:389-93
Harris, M E; Wang, Y; Pedigo Jr, N W et al. (1996) Amyloid beta peptide (25-35) inhibits Na+-dependent glutamate uptake in rat hippocampal astrocyte cultures. J Neurochem 67:277-86
Harris, M E; Hensley, K; Butterfield, D A et al. (1995) Direct evidence of oxidative injury produced by the Alzheimer's beta-amyloid peptide (1-40) in cultured hippocampal neurons. Exp Neurol 131:193-202
Harris, M E; Carney, J M; Cole, P S et al. (1995) beta-Amyloid peptide-derived, oxygen-dependent free radicals inhibit glutamate uptake in cultured astrocytes: implications for Alzheimer's disease. Neuroreport 6:1875-9
Hensley, K; Butterfield, D A; Mattson, M et al. (1995) A model for beta-amyloid aggregation and neurotoxicity based on the free radical generating capacity of the peptide: implications of ""molecular shrapnel"" for Alzheimer's disease. Proc West Pharmacol Soc 38:113-20
Harris, M E; Carney, J M; Hua, D H et al. (1994) Detection of oxidation products in individual neurons by fluorescence microscopy. Exp Neurol 129:95-102
Rose, S; Floyd, R A; Eneff, K et al. (1994) Intestinal ischemia: reperfusion-mediated increase in hydroxyl free radical formation as reported by salicylate hydroxylation. Shock 1:452-6
Carney, J M; Carney, A M (1994) Role of protein oxidation in aging and in age-associated neurodegenerative diseases. Life Sci 55:2097-103

Showing the most recent 10 out of 34 publications