1.4 Free Radical injury Flashcards Preview

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Flashcards in 1.4 Free Radical injury Deck (19):
1

What, technically, is a free radical?

Chemical species with an unpaired electron in the outer orbit

2

What is the sequence of chemical that are formed with adding e- to oxygen?

Superoxide
H2O2
OH*
H2O

3

What are the metals that classically produce free radicals?

Cu
Fe

4

What free radical is generated from ionizing radiation hitting water?

OH*

5

What is the most damaging free radical?

OH*

6

What is the name of the reaction that generates free radicals from Fe?

Fenton reaction

7

What is the underlying mechanism of damage in both Wilson's disease, and hemochromatosis?

Free radical production and damage

8

What is the MOA of the drug used to treat acetaminophen overdose?

N-acetylcysteine--L-cysteine is a precursor to the biologic antioxidant glutathione. Hence administration of acetylcysteine replenishes glutathione stores

9

What are the two major ways that free radicals cause damage?

-Peroxidation of lipids
-Oxidation of DNA and proteins

10

What are the three major mechanisms by which free radicals can be eliminated?

-Antioxidants
-Enzymes
-Metal carrier proteins

11

What are the three major enzymes involved in the breakdown of free radicals?

-SOD
-Glutathione peroxidase
-Catalase

12

What is the enzyme that breaks down superoxide? What does it turn this into?

Superoxide dismutase

H2O2

13

What is the enzyme that breaks down H2O2? What does it turn this into?

Catalase

OH*

14

What is the enzyme that breaks down OH*? What does it turn this into?

Glutathione peroxidase

15

What is the chemical that was classically found in the dry cleaning industry that is a major producer of free radicals?

CCl4

16

Where does CCl4 get metabolized? What happens to the metabolite generated?

p450- system of the liver

CCl3 damages hepatocytes

17

What is the classic histological change that occurs with CCl3 injury? Why?

Fatty change, d/t disruption of apolipoprotein synthesis and buildup of lipids

18

What causes reperfusion injury?

When oxygen returns, PMNs react to the dead tissue and produce free radicals, which the cells cannot handle d/t loss of protective mechanisms

19

What causes the continued rise in troponin with catheterization of the heart?

reperfusion injury