Minerals ( Cu & Zn )

Haseeb TariqRoll no # 32

Copper

Body contains about 100 mg of Cu.

Serum Cu: The copper concentration of plasma is about 100-200 mg/dl

95% is tightly bound to ceruloplasmin

Rest is loosely held with albumin

Normal conc. Of serum ceruloplasmin is 25-50 mg/dl

Dietary Requirements

Adults 2-3 mg/day

Infants and children 0.5-2 mg/day

Sources

Organ Meat

Egg Yolk

Cereals

Nuts

Green leafy vegetables

Milk (a poor source)

Absorption

About 10% of the dietary Cu is absorbed

Absorption occurs in duodenum

Metallothionein facilitates copper absorption. Uptake inhibitors are

Phytates

Zinc

Molybdenum

Excretion

Under normal 85-99% is excreted in the faeces.

Remaining is excreted via urine

Retained Cu depends on the Cu status in tissues.

Biochemical Functions:

Essential constituent of several enzymes

Cu is a constituent of ALA synthase, needed for heme synthesis

Helps the absorption of Fe

A copper containing protein called serum Ferro-Oxidase II participates in oxidation of Fe2+

Help in the bone formation.

Maintains the structure of myelin sheath of nerves

Prevents cachexia.

Cu helps to form insoluble elastin fibers by cross linking the soluble proelastin chains.

Cu deficiency:

Loss of weight

Bone disorders

Anemia Microcytic hypochromic

Change in hair colour

Involves atrophy of myocardium

Histopathological changes in cerebrum, brainstem, and spinal cord.

Demyelinated nerves and non coordinated movements.

Clinical Conditions related to Cu:

Wilson’s Disease Low serum Cu levels

Increased excretion of Cu

Accumulation in: Liver: Hepatic cirrhosis

Brain: Dysfunction of lenticular region of brain (brain necrosis)

Kidney: Aminoaciduria

Eye: Deposition in Descemet’s membrane(Kayser-Fleischer ring)

Menke’s disease

Acaeroplasminaemia

Zinc

Zinc is particularly an intracellular element.

The total content of zinc is about 2 g.

Blood contains about 650-680µg/100ml

Serum Zinc: Conc. in serum is about 100mg/dl.

Erythrocytes contain higher conc. of zinc

Dietary requirements:

Adults 10-15mg/day

Pregnancy & Lactation increased about 50%

Sources:

Meat

Fish

Eggs

Milk

Beans

Nuts

Absorption:

Mainly absorbed in duodenum & ileum

Animal source is better than vegetable source

Small peptides and amino acids promote Zn absorption

Inhibitors Phytates

Phosphates

Calcium

Iron

Excretion:

In adult person about 9.0 mg of zinc is lost via faeces.

0.5 mg is lost in urine.

Trace amount is lost via sweat.

Biochemical Functions:

Role in enzyme action

Role in vitamin metabolism

Role in insulin secretion

Prevents dwarfism and hypogonadism

Role in wound healing

Clinical Aspect:

Acrodermatitis Enteropathica

Diabetes mellitus is related to deficiency of zinc in pancreas

Has reduced amount in leukemia

Malignancies

Atherosclerosis

Hepatic diseases

Acute myocardial infarction

Sickle Anemia

Dermatitis

Helps regulatory proteins to bind with DNA

Superoxide Dismutase

The enzyme is found in cytosol of liver , brain and blood cells.

It contains two Cu & Zn ions each.