Copper (The Second Micromineral) Flashcards
Total body copper content
100mg
Where is copper absorbed?
Duodenum
How is copper transported?
Transport from gut bound to a protein called metallothionein
What are the sources of copper?
Liver, kidney, meat, egg yolk, cereals, nuts, green vegetables
What factors can decrease the absorption of copper?
Phytate
Amount of copper in the plasma
100-200µg/dL
95% of this is tightly bound to protein Ceruloplasmin
What are the metabolic roles of calcium?
Iron metabolism: Ceruloplasmin (copper containing protein) converts ferrous to ferric, (the form in which iron is transported by transferrin). Cu2+ converted to Cu+ by absorbing an electron from Fe2+ forming Fe3+
As prosthetic group of many enzymes and proteins
Helps in maturation of elastin: Lysyl oxidase (a copper containing enzyme) causes oxidation of lysine amino acids which helps in conversion of proelastin into elastin (structural protein)
Scavenging of Free Radicals
Necessary for synthesis of hemoglobin: Component of ALA synthase
What conditions may be caused by deficiency of copper?
Microcytic hypochromic anemia (Iron resistant) – Copper is needed for hemoglobin formation
Demyelination of neurons, fragility of arteries, hypopigmentation of skin and hair
Menkes Kinky hair syndrome - Defective intestinal absorption of copper causes depigmentation of hair
What is Wilson’s disease?
Autosomal recessive defect in ceruloplasmin synthesis
As a result, copper is free in plasma; intestinal absorption increases; and gets deposited in tissues - brain, liver, kidney etc. and damage them
Signs+Symtoms of Wilson’s disease
Most common presentation liver cirrhosis
Kayser-Fleischer rings - Formed by the deposition of copper in the cornea
Serum ceruloplasmin levels < 20 mg/dL (reference range 20-40 mg/dL) in approximately 90% of patients with Wilson disease
The urinary copper excretion rate is greater than 100 mcg/day
Treatment for Wilson’s disease
Therapy is lifelong use of chelating agents (eg, penicillamine, trientine)
