Catecholamines - Blood

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Why is the Test Performed?

This test is used primarily to screen for, diagnose, and monitor treatment of pheochromocytoma or neuroblastoma.

Catecholamines are chemically similar small molecules derived from tyrosine, an amino acid. The major catecholamines are dopamine, norepinephrine, and epinephrine (which used to be called adrenalin).

• Dopamine is a neurotransmitter (a chemical used to transmit impulses between nerve cells), mainly found in the brain.
• Norepinephrine is the primary neurotransmitter in the sympathetic nervous system (controls "fight or flight" reactions) and is also found in the brain.
• Epinephrine is not only a brain neurotransmitter but also a major hormone in the body. Epinephrine is secreted from the adrenal medulla in response to low blood glucose, exercise, and various forms of acute stress. Epinephrine causes several responses:
  • A breakdown of glycogen to glucose in the liver
  • The release of fatty acids from fat tissue
  • Vasodilation of small arteries within muscle tissue
  • Increase in rate and strength of the heartbeat