The vascular endothelium is a significant source of reactive oxygen species and a critical target for tissue injury due to overproduction of oxygen free radicals. Excessive production of reactive oxygen species including superoxide (O2-), hydrogen peroxide (H2O2) and hydroxyl radical (OH-) occurs secondary to diverse phenomena including trauma, acute inflammation sepsis, tissue ischemia-reperfusion, oxygen toxicity and exposure to xenobiotics capable of redox cycling. Oxidant-induced alteration of endothelial cell structure, function or barrier properties can result in modification of endothelial vasoactive properties, increased vascular permeability leading to edema and initiation of other pathologic processes, including platelet aggregation, atherogenesis and activation of neutrophils. Fulfillment of the Specific Aims of the proposal will illuminate mechanisms of oxygen radical injury to metabolically and functionally unique large vessel and microvascular-derived indothelial cells isolated from thoracic aorta and brain capillaries. cells will be examined from both a biochemical and functional perspective. Free radical metabolism studies will be performed in concert with pharmacologic interventions for oxidant damage, which include conjugation of antioxidant enzymes to high molecular weight surface-active molecules and entrapment of antioxidant enzymes in liposomes (which serve as vectors for intracellular enzyme entry). Radioisotopic techniques and absorption and fluorescence spectroscopy will be applied for both identification and quantitation of reactive oxygen species in specific cellular compartments and after release from and intact cells. Controlled manipulation of antioxidant defenses via conjugated or liposome- entrapped antioxidant enzymes will also yield mechanistic information aboun generation and reactions of specific oxygen metabolities in endothelial cells. Measurement of free radical injury to cells and changes in vascular metabolic and barrier functions after oxidant stress will provide a practical means to test the capacity of antioxidant agents in preventing oxidant- mediated vascular injury. These proposed studies represent a combination of cell biology, new drug delivery technologies and sophisticated approaches to measuring oxidant production and reactions in intact cell systems. From this, we will better understand mechanisms of vascular free radical production and injury. Achieving this, we also gain insight from both biochemical and cellular perspective into the rational use of antioxidant agents for therapeutic intervention in tissue pathology secondary to overproduction of reactive oxygen metabolites.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS024275-05
Application #
3408677
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1987-07-01
Project End
1992-06-30
Budget Start
1991-07-01
Budget End
1992-06-30
Support Year
5
Fiscal Year
1991
Total Cost
Indirect Cost
Name
University of Alabama Birmingham
Department
Type
Schools of Medicine
DUNS #
004514360
City
Birmingham
State
AL
Country
United States
Zip Code
35294
Ma, D; Himes, B T; Shea, T B et al. (2000) Axonal transport of microtubule-associated protein 1B (MAP1B) in the sciatic nerve of adult rat: distinct transport rates of different isoforms. J Neurosci 20:2112-20
Ma, D; Chow, S; Obrocka, M et al. (1999) Induction of microtubule-associated protein 1B expression in Schwann cells during nerve regeneration. Brain Res 823:141-53
Tint, I; Slaughter, T; Fischer, I et al. (1998) Acute inactivation of tau has no effect on dynamics of microtubules in growing axons of cultured sympathetic neurons. J Neurosci 18:8660-73
Black, M M; Slaughter, T; Moshiach, S et al. (1996) Tau is enriched on dynamic microtubules in the distal region of growing axons. J Neurosci 16:3601-19
Nothias, F; Boyne, L; Murray, M et al. (1995) The expression and distribution of tau proteins and messenger RNA in rat dorsal root ganglion neurons during development and regeneration. Neuroscience 66:707-19
Black, M M; Slaughter, T; Fischer, I (1994) Microtubule-associated protein 1b (MAP1b) is concentrated in the distal region of growing axons. J Neurosci 14:857-70
Radi, R; Bush, K M; Freeman, B A (1993) The role of cytochrome c and mitochondrial catalase in hydroperoxide-induced heart mitochondrial lipid peroxidation. Arch Biochem Biophys 300:409-15
Panus, P C; Radi, R; Chumley, P H et al. (1993) Detection of H2O2 release from vascular endothelial cells. Free Radic Biol Med 14:217-23
Radi, R; Cosgrove, T P; Beckman, J S et al. (1993) Peroxynitrite-induced luminol chemiluminescence. Biochem J 290 ( Pt 1):51-7
Panus, P C; Wright, S A; Chumley, P H et al. (1992) The contribution of vascular endothelial xanthine dehydrogenase/oxidase to oxygen-mediated cell injury. Arch Biochem Biophys 294:695-702

Showing the most recent 10 out of 23 publications