MECHANISM OF CELL INJURY

Question 1

1. the cellular response to injurious stimuli is dependant on the type of injury,
   its duration and its severity.

Answer 1

GENERAL CONSIDERATION

Question 2

2. consequences of an injurious stimulus are dependent on the?

Answer 2

1. type of cell injured
2. current status,

Question 3

4 intracellular systems are particularly vulnerable to injury.

Answer 3

CELL MEMBRANE
MITOCHONDRIA
PROTEIN SYNTHESIS
GENETIC APPARATUS

Question 4

3 Mecahanism of cell injury

Answer 4

1.GENERAL CONSIDERATIONS
2.BIOCHEMICAL MECHANISM
3.CHEMICAL INJURY

Question 5

cell injury occurs when the free radical generation overwhelms
antioxidant defense mechanisms.

Answer 5

FREE RADICAL INDUCED INJURY

Question 5

ATP depletion and ↓ ATP synthesis are common consequences of
both ischemic and toxic injury.

Answer 5

ATP DEPLETION

Question 6

4 Generation of free radicals

Answer 6

CELLULAR METABOLISM
IONIZING RADIATION
DEVALENT METALS

Question 7

hydrolyzes water into hydroxyl (OH) and
hydrogen (H)free radicals.

Answer 7

IONIZING RADIATION

Question 8

the transition metals (copper and iron), accept or donate free electrons during certain intracellular reactions,

Answer 8

DEVALENT METALS

Question 9

small amount produce from cell redox reactions, intracellular oxidase, excess of O2, altered metabolism

Answer 9

CELLULAR METABOLISM

Question 10

Important reactants

Answer 10

SUPEROXIDE ANION-O2
HYDROXL RADICAL-OH
HYDROGEN PEROXIDE- H202
PEROXYNITTE- ONOO

Question 11

Main site of damage

Answer 11

DAMAGE OF MEMEBRANE
DAMAGE OF PROTEIN
DAMAGE TO DNA

Question 12

Protective mechanism of cell

Answer 12

1. STORGAE & TRANSPORT PROTEINS
2. ANTIOXIDANTS
3. ENZYME NEUTRALIZING FREE RADICALS
4. SUPEROXIDE DISMUTASE
5. CATALASE

Question 13

can catalyze formation of reactive oxygen
forms; they are minimized by being bound to storage and transport proteins

Answer 13

IRON AND COPPER

Question 14

either block the formation of free radicals or inactivate/ scavenge them:

Answer 14

ANTIOXIDANTS

Question 15

a selenium-containing enzyme
which catalyzes GSH to GSSG.
- this enzyme also catalyzes the reduction of lipid peroxides by glutathione, preventing propagation of lipid
peroxidation reactions.

Answer 15

GLUTATHIONE PEROXIDASE

Question 16

catalyzes the conversion of
O2-.to H2O2.

Answer 16

Superoxide dismutase (SOD)

Question 17

In humans and dogs this toxicity is detoxified in the liver to glucurunide & sulfate conjugates then excreted in the urine

Answer 17

ACETAMINOPHEN TOXICTY

Question 18

this animal are deficient in glucuronyl transferase & large portion of acetaminophen toxicity.

Answer 18

CAT

Question 19

CCL4

Answer 19

Carbon tetrachloride toxicity

Question 20

is highly reactive and causes lipid peroxidation (autocatyzing) →see severe and rapid membrane destruction → ↓protein synthesis (30
min); ER swelling & ribosomal dissociation (2 hrs.).

Answer 20

CCL3

Question 21

this animals (compared to humans) produce relatively more of the metabolite “para-aminophenol”, which is released from the liver cells and results in oxidative damage to hemoglobin

Answer 21

CAT AND DOGS