Disorders of Iron Kinetics and Heme Metabolism

What is the most critical metal in the body?

Iron

What are cytochromes and where are they found in the body?

Heme containing proteins that are found in the mitochondria and are vital to the electron transport chain (production of ATP)

What is Irons role in the body?

It is essential for oxygen transport and is attached to HGB molecules in the RBC

Where is Iron found in the body?

• 65% is housed in HGB molecules

• 25% is stored in the form of ferritin and hemosiderin

• 10% in myoglobin, cytochromes, iron-containing enzymes, plasma

The body has no mechanism for active excretion, what does this mean?

The body tightly regulates the amount of iron it takes via absorption in the intestines

What is the iron storage capacity for men?

2.5-4g

What is the iron storage capacity for women?

2-3g

Why is iron recycled in the body?

So the body can conserve as much as possible

How is iron recycled?

1. Aging RBCs are ingested by macrophages in the spleen

2. HGB is broken down and kept in the form of ferritin

3. Ferritin can be used by erythroblasts when needed

Each HGB molecule can carry how many molecules of oxygen?

4

A decrease in body iron leads to what regarding HGB?

Defective HGB synthesis resulting in a decrease in HGB levels in the body