Free Radical Injury Flashcards
What does partial reduction (gain of an electron) of O2 yield?
(Gaining 1, 2, 3 and 4 electrons)
- O2-. (1 electron)
- H2O2 (2 electrons)
- OH (3 electrons)
- H2O (4 electrons)
How can free radicals be generated pathalogically?
- Ionizing radiation
- Inflammation
- Metals (e.g coooer and iron)
- Drugs and chemicals (e.g acetaminophen)
What is the most damaging free radical?
OH-
What converts O2 to O2-. (superoxide)
NADPH oxidase
What converts superoxide (O2-.) to hydrogen peroxide (H2O2)
Superoxide dismutase
What converts hydrogen peroxide to bleach (HOCl)
Myeloperoxidase
What free radical can be generated by iron?
OH-
What does free radical damage due to acetominophen cause?
Liver necrosis
What will free radicals do to lipids?
Peroxidation of lipids
What will free radicals do to DNA and proteins?
Oxidation of DNA and proteins
What substances can eliminate free radicals?
- Antioxidants (vit A, C, E)
- Enzymes
- Metal carrier proteins (transferrin)
What enzymes eleminate free radicals?
- Super oxide dismutase (o2-. -> H2O2)
- Catalse (H2O2 -> OH)
- Glutathione peroxidase (OH -> H2O)
What converts hydrogen peroxide (H2O2) to OH?
Catalase
What converts OH to H2O?
Glutathione peroxidase
Carbon tetrachloride (CCl4) is converted to carbon trichloride (CCl3.) by what enzyme and in what organ?
P450 in liver
What is the effect of carbon trichloride in the cell?
Cellular swelling
- Rough endoplasmic reticulum will also swell and ribosomes will pop off -> reduces protein synthesis
What proteins repackage fat and cholesterol in the liver and can then transport them out?
Apolipoproteins (prevents fatty liver)
- If fat cannot leave you will get fatty liver disease)
What industry has exposure to CCl4 (carbon tetrachloride)?
- May cause fatty liver disease
Dry cleaning
How does reperfusion damage tissues? (e.g myocytes after MI treated w. PCI)
Once blood returns oxygen and inflammatory cells will create free radicals which will continue injury
- Cardiac enzymes will increase after treatment
