Lecture 1

Question 0

give examples of manmade chemicals and natural products

Answer 0

manmade chemicals = pesticides, cleaning products, pharmaceuticals, industrial chemicals, etc.

natural products = vitamins, minerals, animal venoms

Question 1

father of toxicology

Answer 1

Paracelsus

“all substances are poisons. the right dose differentiates poison from remedy.”

Question 2

toxic =

Answer 2

poisonous

Question 3

toxicology is concerned with

Answer 3

identifications, treatment, and assessing risks of poisons

Question 4

toxicant =

Answer 4

compound that causes toxicity

Question 5

xenobiotic =

Answer 5

foreign substance

Question 6

what are the 4 factors that influence toxicity

Answer 6

toxicant, exposure, subject, environment

Question 7

what are examples of factors related to toxicant

Answer 7

chemical and biological properties - mechanism of action, potency, size, charge, etc.

Question 8

examples of factors related to exposure

Answer 8

dose, concentration, route, duration, etc

Question 9

examples of factors related to subject

Answer 9

breed, species, age, etc

Question 10

examples of factors related to the environment

Answer 10

temperature, bioavailability

Question 11

what are the 3 classifications of chemical interactions in toxicity

Answer 11

additive - 2 + 2 = 4 most chemicals act this way
antagonistic - some chemicals block toxicosis
synergism - very rare when 2 + 2 = 6. chemicals have greater effect when together

Question 12

No Observable Adverse Effect Level (NOAEL):

Answer 12

the maximum dose that causes no adverse effect

Question 13

Lowest Observable Adverse Effect Level (LOAEL):

Answer 13

the minimum dose that can cause an adverse effect

Question 14

threshold dose

Answer 14

minimum dose to produce reaction; indicates there is a “safe” dose

Question 15

LD50 =

Answer 15

dose producing death in 50% of animals

Question 16

exposure classifications:

Answer 16

acute
sub-acute/sub-chronic: exposure over 7 to 90 days
chronic: prolonged exposure (6 months to lifetime)

Question 17

definition of ADME

Answer 17

study of the movement and disposition of the toxicant in the organism

Question 18

what does ADME stand for

Answer 18

adsorption - uptake of material
distribution - from blood to tissues
metabolism - enzymatic conversion
excretion - elimination from body

Question 19

in what 3 discussed ways can chemcials be absorbed into the body?

Answer 19

lungs
gut
dermis

Question 20

the most important toxicants are absorbed by what 2 routes?

Answer 20

skin and GI (oral and dermal)

Question 21

list routes of absorption from fastest to slowest

Answer 21

IV –> pulmonary –> IM –> intraperitoneal –> oral –> cutaneous

Question 22

what is the central medium of distribution of chemicals that targets organs?

Answer 22

blood

Question 23

what makes a certain tissue susceptible to particular chemicals?

Answer 23

electric charge, transporters, co-transporters, etc.

Question 24

definition of biotransformation

Answer 24

biological conversion of a chemical compound (exogenous or endogenous) into a second compound or metabolite

Question 25

what is the primary biochemical pathway of xenobiotic metabolism?

Answer 25

biotransformation

Question 26

what requires enzyme catalysts?

Answer 26

biotransformation

Question 27

enzyme catalysts are divided into what 2 groups?

Answer 27

phase 1 and phase 2 reactions

Question 28

what are the two main sites of biotransformation reactions?

Answer 28

liver and kidney

Question 29

why are the liver and kidney the most common sites of biotransformation reactions?

Answer 29

1. highest enzymatic concentration | 2. highest blood flow

Question 30

``` Phase I reactions whats it do: reaction type: reactive groups: action: ```

Answer 30

whats it do: increase hydrophilicity by adding reactive groups reaction type: oxidation/reduction reactive groups: hydroxyl, carboxyl, thiol action: adds on functional groups making the compound more soluble and therefore more easily excreted

Question 31

``` Phase 2 whats it do: reaction type: reactive groups: action: ```

Answer 31

whats it do: inactive conjugates that form and foster elimination reaction type: conjugation reactions reactive groups: acetate, glucoronic acid, glycine, glutathione action: bigger proteins that stick bigger conjugates onto toxicant making molecule more soluble

Question 32

biotransformation can lead to:

Answer 32

``` enhanced elimination detoxification sequestration redistribution activation ```

Question 33

what are some examples of species differences in biotransformation

Answer 33

cats deficient in glucuronidation dogs deficient in acetylation guinea pigs and rats deficient in N-hydroxlation pigs deficient in sulfation

Question 34

effects of metabolism on bioactivation

Answer 34

metabolism usually detoxifies a compound and increases its elimination

Question 35

definition of bioactivation

Answer 35

metabolism increases the toxicity of a compound

Question 36

3 examples of bioactivation:

Answer 36

benzo{a}pyrene, aflatoxin, acetaminophen

Question 37

half-life =

Answer 37

how long it takes for 50% of compound to degrade

Question 38

first-order elimination

Answer 38

constant fraction of chemical eliminated

Question 39

zero-order =

Answer 39

constant amount of chemical eliminated, typically means that processes are saturated

Question 40

what two ways do toxicants cause toxicity?

Answer 40

1. cellular damage | 2. organ system dysfunction

Question 41

top 10 pet toxins

Answer 41

1. pharmecuticals 2. insecticides 3. NSAIDS 4. househould products 5. human foods 6. vet meds 7. chocolate 8. rodenticide 9. toxic plants 10. lawn products

Question 42

top 10 most dangerous foods for dogs

Answer 42

1. alcohol 2. avocados 3. chocolate 4. coffee and caffeine 5. fruit with pits/seeds 6. grapes and raisins 7. macadamia nuts 8. onion and garlic 9. xylitol (artificial sweetener) 10. yeast dough