Heavy Metals

Question 1

species most vulnerable to lead poisoning?

Answer 1

waterfowl

Question 2

main route of absorption of lead?

Answer 2

ingestion

Question 3

T/F: patient deficient in vit d, Ca, Zn, or Fe absorbs Pb better?

Answer 3

YES

Question 4

most common source of lead toxicosis is????

Answer 4

lead based paints (paint chips)

Question 5

MOA of Pb toxicosis?

Answer 5

interferes w cellular function, substitutes Ca, Zn, Mg and Fe, competes w/ Ca in bone and alters Ca movement across membrane

Question 6

Target tissues of Pb toxicity?

Answer 6

GIT, blood and CNS

Question 7

chronic exposure of Pb effect on blood?

Answer 7

inhibition of heme synthesis, anemia, delayed RBC maturation, stippling of RBC

Question 8

Pb toxicosis can cause brain edema?

Answer 8

yes

Question 9

GIT signs of Pb toxicosis?

Answer 9

caustic nature of lead salts, anorexia, salivation, vomiting, diarrhea, constipation, rumen antony

Question 10

CNS signs of Pb toxicosis?

Answer 10

inhibition of neurotransmitters, spontaneous release of dopamine, Ach, GABA - aka big mess!

Question 11

which species show CNS depression w/ Pb toxicosis?

Answer 11

horses and sheep

Question 12

Most common chelator used in Pb toxicosis tx???

Answer 12

calcium disodium EDTA

Question 13

a farmer calls you freaking out because his animals all ate a bunch of old batteries that he left out. terrible!!! he mentions he has some disodium EDTA on hand and is wondering if he should give it to his critters. is this ok??

Answer 13

NOOOOOOO. his idea of using a chelator is ideal because they have Pb toxicosis but, need to use CALCIUM disodium EDTA not just disodium EDTA (risk hypocalcemia and kidney damage)

Question 14

should you tx Pb toxicosis w/ activated charcoal?

Answer 14

nooo not recommended

Question 15

most common source of exposure of Zn is???

Answer 15

ingestion (pennies, galvanized metals, ointments, supplements)

Question 16

Once absorbed, Zn travels to liver bound to plasma proteins??

Answer 16

yassss

Question 17

Zn undergoes enterohepatic recirculation?

Answer 17

yes

Question 18

4 major tissues affected by Zn toxicosis?

Answer 18

RBC, kidney, liver, pancreas

Question 19

excess Zn interferes w/ absorption of other metals???

Answer 19

ya

Question 20

Zn causes intravascular hemolysis! what would you see in urine?

Answer 20

hemoglobinuria (bc hemolytic anemia)

Question 21

A client comes to you worried because her dog ate a bunch of hand warmer packets. What heavy metal toxicity are you worried about??

Answer 21

Iron!!!

Question 22

Rust is very toxic?

Answer 22

no, generally non toxic

Question 23

Toxicity of Fe due to??

Answer 23

formation of ROS, cellular damage, tissue death, organ failure

Question 24

which is more of an irritant? organic or inorganic iron??

Answer 24

inorganic

Question 25

which is more of an irritant? ferrous 2+ or ferric 3+??

Answer 25

ferric!

Question 26

primary effect of Fe??

Answer 26

GIT CV system and liver --> shock and death!

Question 27

when is chelation therapy indicated in Fe toxicosis?

Answer 27

only in severe cases within 12h of ingestion