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BIOL3207 Toxicology > Chapter 5 lecture 7-8 > Flashcards

Chapter 5 lecture 7-8 Flashcards

1
Q

What is Toxicodynamic?

A
  • the relationship between the concentration of a toxicant at the site of action &
  • the toxic effect at the level of molecule, cell, tissue, organ or organism.
  • What the toxicant do to us
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2
Q

What are the factors influencing toxicity?

A
  1. Dosage
  2. Property
  3. Duration
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3
Q

What are the 7 factors affecting toxicity?

A
  1. Species
  2. Age & sex
  3. Exposure route
  4. Dosage, especially dose-time relationship
  5. ADME
  6. Form and innate chemical activity
  7. Presence of other chemicals
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4
Q

How is the toxic response varying between species?

A
  1. Differences in metabolism
  2. anatomical or physiological differences
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5
Q

What is selective toxicity?

A
  • The difference between in toxicity
  • Basis for pesticides and drugs
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6
Q

How does Age affect toxicity?

A

Some are more toxic to infants/elderly
* Parathion & Nitrosamines: More toxic & carcinogenic respectively to young animals.

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7
Q

How does Sex affect toxicity?

A
  • Male rats are 10x sensitive than females for DDT
  • Female rats are 2x sensitive for parathions
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8
Q

Why exposure route is influencing toxicity?

A

Difference in absorption and distribution. Eg. ingested -> GI-> Liver
Blood -> other organs -> Liver

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9
Q

Dosage is important for toxicity, T/F?

A

Of course true
Also, the the toxic mechanisms and target organs are different for acute and chronic toxicity

Ethanol : CNS depression :: Liver cirrhosis
Arsenic: GI damage :: Skin/Liver Cancer

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10
Q

How does Absorption affect toxicity?

A
  1. The ability to absorb
  2. The rate and extent of absorption
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11
Q

How ADME affect toxicity?

A

D: lipid solubility
M: Detox and bioactivation
E : Site and rate of excretion

Kidneys are the filter for blood serum, lipid-soluble toxicants are reabsorbed and concentrated in kidney cells.

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12
Q

How does “Form and innate chemical activity” affect toxicity?

A

Form: Different form different toxicity
Liquid mercury is more toxic than vapour

Innate chem: Some can quickly damage cells -> cell death
-hydrogen cyanide binds to cytochrome oxidase resulting in cellular hypoxia and rapid death
-nicotine binds to cholinergic receptors in the CNS altering nerve conduction and inducing gradual onset of paralysis

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13
Q

Organ specific toxicity vs Systemic toxicity

A

Specific at target oragn 1 site vs Toxic effects can be multiple sites

The acute, sub, chronic toxicity are under systemic toxicity.

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14
Q

Describe the systemic toxic effect: Carcinogenicity.

A
  • Initiation: normal cell undergoes irreversible change-> mutation change DNA
  • Promotion: Promote mutated cells to progress to cancer
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15
Q

Recall what are tumor, benign tumours and malignant tumors

A
  • tumor is simply an uncontrolled growth of cells
  • Benign tumors grow at the site of origin; do not invade adjacent tissues or metastasize; and generally, are treatable.
  • Malignant tumors (cancer) invade adjacent tissues or migrate to distant sites (metastasis). They are more difficult to treat and often cause death.
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16
Q

Describe systemic toxic effect: Developmental toxicity

A
  • adverse toxic effects to the developing embryo or fetus.
  • result fromparent before conception or to the mother and her developing embryo-fetus.
17
Q

What are the 3 types of developmental toxicity?

A
  1. Embryolethality: Failure to conceive, spontaneous abortion or stillbirth
  2. Embryotoxicity: Growth retardation, or delayed growth of specific organ systems
  3. Teratogenicity : Irreversible conditions that leave permanent birth defects in living offstring (e.g. missing limbs)
18
Q

How is developmental toxicity developed?

A
  • Act directly on embryo cells
  • Induce mutation in parent’s germ cells
19
Q

Describe systemic toxic effects:
Genetic Toxicity

A

results from damage to DNA and altered genetic expression

20
Q

What are the 3 types of genetic toxicity?

A
  1. Gene mutation
  2. Chromotion aberration: Alter chromosome structure
  3. Aneuploidy/polyploidy: Decrease/Increase Chromosome no.
20
Q

What are the 3 types of genetic toxicity?

A
  1. Gene mutation
  2. Chromotion aberration: Alter chromosome structure
  3. Aneuploidy/polyploidy: Decrease/Increase Chromosome no.
21
Q

Name some examples of blood and cardiovascular toxicity

A

-hypoxia due to carbon monoxide binding of hemoglobin preventing transport of oxygen
-decrease in circulating leukocytes due to chloramphenicol damage to bone marrow cells
-leukemia due to benzene damage of bone marrow cells
-arteriosclerosis due to cholesterol accumulation in arteries and veins

22
Q

Give some examples of dermal toxicity

A

-dermal irritation due to skin exposure to gasoline
-dermal corrosion due to skin exposure to sodium hydroxide
-dermal hypersensitivity due to skin exposure to poison ivy
-skin cancer due to ingestion of arsenic or skin exposure to UV light

23
Q

Give some examples of eye toxicity

A

Cornea and conjunctiva directly exposed to toxicants
* Conjunctivitis and cornea erosion
-acids and strong alkalis may cause severe corneal corrosion
-corticosteroids may cause cataracts
-methanol (wood alcohol) may damage the optic nerve

24
Q

Give some examples of hepatoxicity

A

toxicity to the liver, bile duct, and gall
bladder
* Cirrhosis-> chronic fibrosis of liver due to alcohol

25
Q

Give some examples of immunotoxicity

A

Toxicity to immune system
-contact dermatitis due to exposure to poison ivy
-systemic lupus erythematosus in workers exposed to hydrazine
-immunosuppression by cocaine
-leukemia induced by benzene

26
Q

Why are kidneys highly susceptible?

A
  1. High volume of blood flow
  2. Filtrates a large amount of toxins
27
Q

Give examples of Nephrotoxicity

A

-decreased ability to excrete body wastes
-inability to maintain body fluid and electrolyte balance
-decreased synthesis of essential hormones (e.g.,
erythropoietin)

28
Q

Give examples of Neurotoxicity

A

Damage to CNS and PNS
-neuronopathies (neuron injury)
-axonopathies (axon injury)
-demyelination (loss of axon insulation)
-interference with neurotransmission

29
Q

Give examples of Reproductive toxicity

A

Target reproductive systems
-decreased libido and impotence
-infertility
-interrupted pregnancy (abortion, fetal death, or premature
delivery)
-infant death or childhood morbidity
-altered sex ratio and multiple births
-chromosome abnormalities and birth defects
-childhood cancer

30
Q

Give examples of Respiratory toxicity

A

UPPER & LOWER respiratory system
-pulmonary irritation
-asthma/bronchitis
-reactive airway disease
-emphysema
-allergic alveolitis
-fibrotic lung disease
-pneumoconiosis
-lung cancer

BIOL3207 Toxicology (7 decks)

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