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Norepinefrin (noradrenalin)

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Norepinephrine (Noradrenaline) – A Catecholamine Neurotransmitter and Hormone

Norepinephrine is a catecholamine that functions as both a neurotransmitter and a hormone. It is synthesized from dopamine in postganglionic cells of the sympathetic nervous system, the adrenal medulla, and the central nervous system. Norepinephrine shares many similarities with epinephrine (adrenaline).

In the bloodstream, most norepinephrine is produced by sympathetic nerve endings, while only about 7% originates from the adrenal medulla.

  • 1 yaşa qədər uşaqlar tədqiqatdan 30-40 dəqiqə əvvəl yemək yeməməlidirlər.
  • 1 yaşdan 5 yaşa qədər uşaqlar müayinədən 2-3 saat əvvəl yemək yeməməlidirlər.
  • Sınaqdan əvvəl 72 saat ərzində pəhrizdən avokado, banan, badımcan, ananas, gavalı, pomidor, qoz xaric edin.
  • Analizdən 12 saat əvvəl yemək yeməyin, təmiz qazsız su içə bilərsiniz.
  • Analizdən 14 gün əvvəl simpatomimetikləri ləğv edin (həkimlə razılaşdırılaraq).
  • Analizdən 24 saat əvvəl dərman qəbul etməyi (həkimlə razılaşdırmaqla) tamamilə istisna edin.
  • Analizdən 24 saat əvvəl fiziki və emosional stressi aradan qaldırın.
  • Analizdən 2 saat əvvəl siqaret çəkməyin.

For children under 1 year: No food for 30–40 minutes before the test.
For children aged 1–5 years: No food for 2–3 hours before the test.
 

  • No food for 12 hours before the test (only water is allowed).
  • Discontinue sympathomimetic drugs 14 days before the test (as per physician’s guidance).
  • Avoid all medications 24 hours before the test (as per physician’s guidance).
  • Eliminate physical and emotional stress 24 hours before the test.
  • Do not smoke for at least 2 hours before the test.
  • Suspicion of a chromaffin tumor (pheochromocytoma, neuroendocrine tumors).
  • Chronic hypertension accompanied by headaches, sweating, and a rapid pulse.
  • Resistant hypertension that does not respond to standard treatment (since hypertension caused by chromaffin tumors is often unresponsive to traditional therapies).
  • Detection of adrenal or neuroendocrine tumors on imaging or genetic predisposition to such tumors.
  • Monitoring patients after treatment for chromaffin tumors.
     

    Test Interpretation and Follow-Up

    Many factors can influence norepinephrine levels, leading to false-positive results. Since chromaffin tumors are rare, an elevated catecholamine level alone does not confirm a diagnosis.

    For an accurate diagnosis, a comprehensive evaluation is required, including:

  • Assessment of the patient’s physical and emotional state.
  • Review of medications and dietary intake.
  • Repeat testing after eliminating interfering factors to determine if catecholamine levels remain elevated.

  • Additional tests for confirmation may include:

  • Blood and/or urine tests for metanephrines (norepinephrine metabolites).
  • MRI or CT imaging to locate potential tumors.