Free Radical Injury Flashcards
Free radicals are chemical species with an _______ in their (inner or outer?) orbit.
unpaired electron
Outer
Free radicals form when chemical bonds are ____ and each fragment keeps ______ in the outer shell (in ____ reactions)
broken
one electron
redox
Physiologic generation of free radicals occurs during ___________ where ___________ (complex ____) transfers electrons to _______.
This Partial reduction yields _______,_______ or _______
oxidative phosphorylation.
Cytochrome C oxidase
IV
oxygen
Superoxide (O-), Hydrogen peroxide (H202), andHydroxyl radicals (OH-).
Pathologic generation of free radicals arises with
Ionizing ____
______
______
Drugs and chemicals
radiation
Inflammation
Transition Metals
Pathologic generation of free radicals arises with
Ionizing radiation — _____ hydrolyzed to ______________
water
hydroxyl free radical
Pathologic generation of free radicals arises with
Inflammation — ______ generates ______ radical ions (__) as well as _____ free radical (____) during _____ dependent killing by _______.
NADPH oxidase
superoxide free; O-
peroxynitrite; ONOO-
oxygen; neutrophils
Pathologic generation of free radicals arises with
Transition Metals (e.g., _____ and iron) —Fe generates _____ radicals ( ____reaction).
Copper
hydroxyl free
Fenton
Pathologic generation of free radicals arises with
Drugs and chemicals — ____ system of liver metabolizes drugs (e.g., acetaminophen), generating free radicals.
P450
Free radicals cause cellular injury via _______ of ______ and ______ of ______ and proteins;
peroxidation of lipids
oxidation of DNA
DNA damage is implicated in ______ and _______
ageing and oncogenesis.
Elimination of tree radicals occurs via multiple mechanisms:
______
_______
______
Antioxidants
Enzymes
Metal carrier proteins
Elimination of tree radicals occurs via multiple mechanisms:
Metal carrier proteins (e.g., ____ for ____ and _____ for ______ )
transferrin ; iron
ceruloplasmin; copper
Elimination of tree radicals occurs via multiple mechanisms:
Antioxidants (e.g., ______ and _______)
glutathione
vitamins A , C, and E
Elimination of tree radicals occurs via multiple mechanisms:
Enzymes
_________ (in _______)
___________ (in _______)
_________ (in _______)
Superoxide dismutase ; mitochondria
Glutathione peroxidase; mitochondria
Catalase; peroxisomes
Elimination of tree radicals occurs via multiple mechanisms:
Enzymes
Superoxide dismutase
—converts _______ (__) to _____
Superoxide; O-
H202
Elimination of tree radicals occurs via multiple mechanisms:
Enzymes
Glutathione peroxidase
—___+ free radical (__) —> ______ and _____
GSH; OH
GSSG and H20
Elimination of tree radicals occurs via multiple mechanisms:
Enzymes
Catalase
converts ______ to ____ and _____
H2O2
O2 and H2O
Other important causes of free radical injury
Carbon tetrachloride (CCl4)
Is Converted to ____, a free radical by ____ system of hepatocytes
Results in cell injury with swelling of ____; consequently, _____ , impairing ____ synthesis.
Can also lead to ___ change
CCl3-
CYP450
RER
ribosomes detach
protein
fatty
Carbon tetrachloride (___) is an ______ used in the ______ industry
CCl4
Organic solvent
dry cleaning
Decreased _________ production lead to fatty change in the liver
apolipoproteins
Other important causes of free radical injury
Ischemia-Reperfusion injury
Return of ____ to ____ tissue results in production of ___-derived free radicals, which further damage tissue.
Leads to a continued rise in ___ enzymes (e.g., ____) after reperfusion of _____ myocardial tissue
blood; ischemic; O2
cardiac; troponin; infarcted
Ischemia- Reperfusion Injury
However, under certain circumstances the restoration of blood flow to cells that have been ischemic (reversibly injured) but have not died (irreversibly injured), can paradoxically exacerbate and produce injury at an accelerated pace.
reversible; irreversible
Decreased blood flow to a tissue or organ is called ______.
ischemia
If the involved cells of the tissue are reversibly injured, the restoration of blood flow (reperfusion) is often ________.
beneficial
