Trace Elements Flashcards
(116 cards)
What are trace elements?
Minerals present in small amounts in living tissues (<1 µg/g wet tissue or <0.01% of body weight).
Which metals are NOT considered trace elements?
Selenium, halogens, fluoride, iodine
FISH
What are essential trace elements?
normal health, function, and development.
Deficiency leads to impairment but can be corrected with supplementation.
Often part of enzymes (metalloenzymes) or proteins (metalloproteins).
What is the difference between trace and ultratrace elements?
Trace elements: Found in mg/L concentration (e.g., iron, copper, zinc).
Ultratrace elements: Found in µg/L concentration (e.g., selenium, chromium, manganese).
What are the specimen requirements for trace element testing?
Urine, serum, plasma, blood, hair, and nail samples.
What factors affect pre-analytical variation in trace element testing?
Time of day
Food intake timing
Tobacco use
etc
What is the preferred tube for trace element collection?
Navy blue top tube (EDTA, serum)
What are the methods used to analyze trace elements?
- Atomic Emission Spectroscopy (AES)
- Atomic Absorption Spectroscopy (AAS)
- Inductively Coupled Plasma-Mass Spectrometry (ICP-MS)
- Quadrupole Mass Spectrometers
- High-Resolution Mass Spectrometers
What is the 1st, 2nd, and 3rd, abundant transition metals?
Iron, Zinc, Copper
How much iron is in the body?
3-5 g
Where is Iron primarily distributed in the body?
Where is Zinc primarily distributed in the body?
Where is Copper primarily distributed in the body?
Where is Cobalt primarily distributed in the body?
Fluoride?
IRON——————
RBCs (~2-2.5 g)
Myoglobin (~130 mg)
Tissues (~8 mg, enzyme activation)
Ferritin & hemosiderin (bone marrow, liver, spleen)
Plasma iron concentration: 3-5 mg
ZINC——————-
Body:
60% in muscle
30 in bone
10 others
Blood:
80% in rbc
17% plasma
3% in wbc
COPPER———————–
high conc: liver (10%), brain, heart, and kidneys
COBALT————
Muscle, liver, fats
CHROMIUM—————–
Liver, spleen, soft tissue, bone
FLUORIDE———————
95 IN BONES AND TEETH
What percentage of dietary iron is absorbed?
About 10% of 1 g/day
In what form must iron be to be absorbed?
A: Fe²⁺ (Ferrous)
What helps convert Fe³⁺ to Fe²⁺ for absorption?
A: - Vitamin C
Ferric reductases
What protein binds iron in the blood for transport?
What what is used for zinc transport?
What what is used for copper transport?
What what is used for chromium transport?
What what is used for magnesium transport?
molybdenum
- Transferrin
- albumin (65); a2 microglobulin (35)
- to liver: albumin, trascupein, LMW (portal system)
- Transferrin, albumin(also bound by beta, gamma, lipoproteins)
- transferrin, albumin, a2 macroglobulin
- a2 macroglobulin, rbc
What is the main function of iron in the body?
Oxygen transport and storage
Who is at high risk for iron deficiency?
A: - Pregnant women
Children & adolescents
Women of reproductive age
What is another name for iron overload?
A:
Hemochromatosis
What is a genetic cause of iron overload?
A: Hereditary hemochromatosis (HFE gene mutation)
What are clinical signs of iron overload?
A: - Skin hyperpigmentation
Liver cirrhosis
Diabetes
Cardiomyopathy
Hypogonadism & impotence
What are the treatments for hemochromatosis?
Therapeutic phlebotomy
Administration of chelators
Transferrin
What are the two types of iron overload?
: Hereditary hemochromatosis and secondary iron overload
What conditions can excess iron contribute to?
A: Arthritis, cardiac arrhythmia, impotence, liver cancer
What is the primary storage protein for iron?
A: Ferritin