Trace Elements

Question 1

Which is the most abundant trace element?

Answer 1

Iron

Question 2

What are the two types of dietary iron?

Answer 2

-Heme sources (Fe2+)
-Non heme sources (Fe3+)

Question 3

Where is iron absorbed? To what efficacy?

Answer 3

proximal small intestine. 3-5%

Question 4

What is the role of EPO in iron absorption?

Answer 4

It will stimulate iron absorption

Question 5

What blood protein binds to Fe3+? Where does this binding occur?

Answer 5

transferrin in the blood

Question 6

Why is it important that iron is bound?

Answer 6

Because it is otherwise and oxidative agent

Question 7

Where is the most iron located in the body?

Answer 7

RBCs

Question 8

What is the tissue binding protein of iron?

Answer 8

ferritin

Question 9

Which two hydroxylases are associated with iron

Answer 9

Tyrosine and tryptophan

Question 10

What two synthesis pathways is iron involved in?

Answer 10

Catecholamine and Serotonin

Question 11

What is the main sign of iron deficiency?

Answer 11

anemia

Question 12

What is the most common cause of iron deficiency?

Answer 12

blood loss

Question 13

What is the most common way an animal lose blood and cause iron deficiency?

Answer 13

GI bleeding (tumors, parasites, etc)

Question 14

List two reasons young animals may need iron supplementation?

Answer 14

-low iron stores
-rapid growth demands expansion of blood volume

Question 15

What is secondary iron deficiency?

Answer 15

There are normal iron levels, but heme cannot be synthesized

Question 16

What are two causes of iron deficiency?

Answer 16

-Chronic lead poisoning
-Vit B6 deficiency (pyridoxal phosphate is a cofactor for delta-ALA synthase)

Question 17

Iron toxicity is rare in vet med, true or false?

Answer 17

true

Question 18

Why is zinc important?

Answer 18

It is an important component of many proteins including >100 enzymes involved in metabolic pathways

Question 19

Where is zinc absorbed and to what efficacy?

Answer 19

the proximal small intestine at 20-30%

Question 20

Why is zinc not stored?

Answer 20

because it has such a high turnover rate

Question 21

How is zinc transported in the blood?

Answer 21

Albumin

Question 22

What are 6 zinc containing enzymes?

Answer 22

-Pepsidases/collagenases
-carbonic anhydrase
-superoxide dismutase
-pyruvate carboxylase
-retinal reductase
-alkaline phosphate

Question 23

What 4 receptors utilize zinc finger motifs?

Answer 23

-RAR
-RxR
-VDR
-Steroid receptors

Question 24

What amino acid does zinc coordinate with for zinc finger formation?

Answer 24

cysteine

Question 25

What is a condition in canines resulting from zinc deficiency?

Answer 25

zinc responsive dermatosis

Question 26

What is the most common cause of zinc toxicity?

Answer 26

penny ingestion

Question 27

What disease can occur because of zinc toxicity?

Answer 27

hemolytic anemia

Question 28

Where is copper absorbed? to what efficacy?

Answer 28

proximal small intestine at 50%

Question 29

What is the major blood carrier of copper

Answer 29

ceruloplasmin

Question 30

What are 4 copper containing enzymes?

Answer 30

Cytochrome c oxidase
superoxide dismutase
dopamine b-hydroxylase
monoamine oxidase (MOA)

Question 31

What is the vitamin and trace element cofactor for dopamine beta hydroxylase?

Answer 31

vitamin C and copper

Question 32

What is the role of ceruloplasmin in iron absorption?

Answer 32

It exhibits a copper dependant oxidase activity which assists in the conversion of Fe 2+ to Fe3+ enabling binding to transferrin

Question 33

What mutation is associated with canine degenerative myelopathy?

Answer 33

superoxide dismutase mutations

Question 34

Describe copper storage hepatopathy. Cause, signs, diagnosis, treatment

Answer 34

occurs primarily in the dog. the inability to excrete copper or excessive dietary copper. Occurs commonly in bedlington terriers. signs: may be asymptomatic, history of lethargy, anorexia, wt loss, v+, d+. Diagnosis: elevated liver values, need dliver biopsy and quant copper analysis for definitive diagnosis. Tx: copper chelators

Question 35

What species is susceptible to copper toxicity? why?

Answer 35

sheep because liver cells have a high affinity for copper and excrete copper to bile at a very low rate

Question 36

What happens w/ copper toxicity in sheep?

Answer 36

Copper accumulation in the liver followed by a sudden release of copper into the blood stream causes hemolysis, icterus, and death