Definition of Catecholamine
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Catecholamine definition - medical term Pronounced cat·e·chol·amine. An amine derived from the
amino acid tyrosine -- examples include epinephrine (adrenaline), norepinephrine
(noradrenaline), and dopamine -- that act as hormones or neurotransmitters. There
are a number of disorders involving catecholamines, including neuroblastoma, pheochromocytoma,
chemodectina, the familial paraganglioma syndrome, dopamine-ß-hydroxalase deficiency,
and tetrahydrobiopterin deficiency
Neuroblastoma is the second most common solid tumor in childhood (after
brain tumors). It usually produce catecholamines. The catecholamine metabolites
vanillylmandelic acid and homovanillic acid can be measured quantitatively in the
urine as a test for the disease.
Pheochromocytoma is a benign tumor derived from the adrenal medulla or
sympathetic paraganglia. The tumor secretes epinephrine and norepinephrine. These
catecholamines cause attacks of hypertension, headache, nausea and vomiting, sweating,
pallor and severe apprehension.
Chemodectoma is another benign tumor of the chemoreceptor system, the
most common types being the carotid body tumor and the glomus jugulare tumor. Also
known as nonchromaffin paraganglioma.
Familial paraganglioma syndrome is an unusual familial disease involving
slow-growing benign tumors -- paragangliomas, glomus tumors, or chemodectomas --
predominantly in the head and neck region. The gene for the disease is on chromosome
11q23. The tumors may lead to disfiguring local swellings, cranial nerve injury,
or involvement of the base of the skull and may cause dysphonia, aspiration, hearing
loss, dysphagia, tinnitus, pain, persistent cough, and shoulder weakness (due to
tumor encroachment on cranial nerves). All individuals with hereditary paragangliomas
inherit the disease gene from their father. This is consistent with genomic imprinting:
the maternally derived gene is inactivated during oogenesis and can be reactivated
only during spermatogenesis.
Dopamine-ß-hydroxalase deficiency is a congenital form of severe orthostatic
hypotension caused by complete absence of the enzyme dopamine-ß-hydroxalase. During
childhood impaired exercise tolerance, fatigue, and episodes of syncope (fainting)
are common. Symptoms from orthostatic hypotension become worse in late adolescence
and in early adulthood.
Tetrahydrobiopterin deficiency is a genetic defect of enzymes required
for the synthesis (production) of catecholamines, resulting in a deficiency in neurotransmitters.
Symptoms begin between two and eight months of age, and include unstable body temperature,
swallowing difficulties, hypersalivation, pinpoint pupils, ptosis of the eyelids,
decreased mobility, drowsiness, and irritability.
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