Catecholamine:Pronounced cat?e?chol?amine. An amine derived from theamino acidtyrosine-- examples includeepinephrine(adrenaline), norepinephrine (noradrenaline), anddopamine-- that act as hormones or neurotransmitters. There are a number of disorders involving catecholamines, including neuroblastoma,pheochromocytoma, chemodectina, thefamilialparaganglioma syndrome, dopamine-?-hydroxalase deficiency, and tetrahydrobiopterin deficiency
Neuroblastomais the second most common solid tumor inchildhood(after brain tumors). It usually produce catecholamines. Thecatecholaminemetabolites vanillylmandelic acid and homovanillic acid can be measured quantitatively in the urine as a test for the disease.
Pheochromocytomais abenigntumor derived from theadrenal medullaor sympathetic paraganglia. The tumor secretes epinephrine and norepinephrine. These catecholamines cause attacks ofhypertension, headache, nausea and vomiting, sweating, pallor and severe apprehension.
Chemodectomais another benign tumor of the chemoreceptor system, the most common types being thecarotidbody tumor and the glomus jugulare tumor. Also known as nonchromaffin paraganglioma.
Familial paraganglioma syndromeis 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,cranialnerve injury, or involvement of the base of the skull and may causedysphonia,aspiration, hearing loss,dysphagia,tinnitus、疼痛持续咳嗽,shoulderweakness (due to tumor encroachment oncranial 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 duringoogenesisand can be reactivated only duringspermatogenesis.
Dopamine-?-hydroxalase deficiencyis acongenitalform of severeorthostatic hypotensioncaused by complete absence of the enzyme dopamine-?-hydroxalase. During childhood impaired exercise tolerance, fatigue, and episodes of晕厥(fainting) are common. Symptoms from orthostatichypotensionbecome worse in late adolescence and in early adulthood.
Tetrahydrobiopterin deficiencyis 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,ptosisof the eyelids, decreased mobility, drowsiness, and irritability.
