(Science: biochemistry, investigation, physiology) a type of biogenic amine derived from tyramine, characterised as alkylamino derivatives of ortho-dihydroxyphenylalkylamines in turn derived from tyrosine.
catecholamines include adrenaline, noradrenaline and dopamine, with roles as hormones and neurotransmitters.
measurement of noradrenaline and adrenaline can be made in blood and urine. Elevations may be seen in pheochromocytoma or neuroblastoma.
normal blood levels of adrenaline should be: 20 ng/ml and normal blood levels of noradrenaline should be 60 ng/ml.