Selective Toxicity

Question 1

Differences between human and bacterial cells:

Answer 1

ribosomes
membrane
cell wall
enzyme
DNA

Question 2

Sulfanilamide resembles:

Answer 2

folic acid

Question 3

why is trimethoprim better than sulfonamide?

Answer 3

Trimethoprim is less toxic to mitochondria, first line for UTIs

Question 4

Cancer drugs target structures or behaviours?

Answer 4

behaviours

Question 5

Methotrexate inhibits what?

Answer 5

purine synthesis

Question 6

Methotrexate resembles what?

Answer 6

Folic acid

Question 7

Is methothrexate selective?

Answer 7

Not really, vaguely

Question 8

Methotrexate is used for cancer and what else?

Answer 8

immuno suppressants

Question 9

what inhibits human dihydrofolate reductase?

Answer 9

methotrexate

Question 10

Is methotrexate good for a fetus?

Answer 10

Nope. Teratogenic, used to terminate ectopic pregs

Question 11

What does 1/5th does of cancer strength methotrexate do?

Answer 11

kills lymphocytes

Question 12

Why don’t ducks get cold feet?

Answer 12

they do but don’t care, coutercurrent exchange

Question 13

Why is the arterial vasculature of the testes squiggly?

Answer 13

enhances countercurrent to keep it cool and high testosterone environment (kind of autocrine)

Question 14

Renal architecture uses countercurrent exchange, what does that mean?

Answer 14

O2 in the artery passes right to the surrounding veins leaving it in relative hypoxia

Question 15

2 reasons why kidneys are so sensitive to O2 changes?

Answer 15

1. uses countercurrent exchange so it’s in relative hypoxia

2. uses ALOT of ATP for transportation of ions etc.

Question 16

What is the last resort for a kidney when renal blood flow is compromised?

Answer 16

prostaglandin-mediated vasodilation

Question 17

What is a ‘triple-whammy’ for kidneys?

Answer 17

diuretic, ACE/AT1 receptor antagonist, PLUS an NSAID = acute renal failure

Question 18

Gentamicin can cause toxicity for kidneys and what else?

Answer 18

ears (ototoxicity), due to attacking hair cells in the cochlea which don’t grow back.

Question 19

Gentamicin ototoxicity is reversible?

Answer 19

Nope.

Question 20

What does paraquat do?

Answer 20

herbicidal, destroy cell membranes, proteins, DNA

Question 21

How is paraquat activated?

Answer 21

photosynthesis/e- transport chain

Question 22

Is paraquat systemic?

Answer 22

Nope. Selective

Question 23

paraquat in humans accumulates where in low doses?

Answer 23

lungs