1.4 Free Radical Injury Flashcards
What are free radicals?
Chemical with an unpaired e- that can induce cellular damage
How are free radicals pathologically generated?
- Radiation
- Inflammation
- Metals
- Drugs
What is the most damaging free radical?
OH. free radical
What is the role of NADPPH?
Converts O2 to O2- (superoxide)
How does hemochromatosis cause tissue damage?
Excess iron creates free radicals that lead to damage
What is Wilson’s disease?
Excess copper
What is one of the main drugs that can lead to the generation of free radicals?
Acetaminophen
What are the main damaging acts of free radicals?
- Peroxidation of lipids
- Oxidation of DNA and proteins
What are some of the main mechanisms for the elimination of free radicals?
- Antioxidants
- Enzymes
- Metal Carriers
Superoxide Dismutase
Removes superoxide
Glutathione Peroxide
Removes OH. free radical
Catalase
Removes peroxide
How does CCl4 cause free radical damage?
It is converted in the P450 system in the liver to CCl3 causing cells to swell with ER swelling and decreasing protein synthesis.
What is the classical histological finding with CCl4 toxicity in the liver?
Accumulation of fat in the liver - fat cant be transported out of the liver
Reperfusion Injury
Ischemia that leads to death of cells can lead to reperfusion injury as O2 presence with inflammatory cells can lead to further damage due to the generation of more free radicals.
