Degradation of Catecholamines: AO COM Pargyline, Nialamide 0A COMT=catechol-O-methyltransferase Diagnosis of pheochromocytoma MAO=monoamine oxidase MAO:associated with outer surface of mitochondia,including those within the terminals of adrenergic fibers. COMT:located mostly in cytoplasm.Rich in liver,kidney;not found in adrenergic neurons. E E 的 Post-synaptic Pre-synaptic NENE Diffusion, Normetanephrine(NMN) metabolism VMA:vanillylmandelic acid(3-Methoxy-4-hydroxymandelic acid) 88 Degradation of Catecholamines: HO HO CH2 NHCH3 OH CH Epinephrine HO HO CH2 NH2 OH CH Norepinephrine HO HO CH2 NH2 CH2 Dopamine HO HO COOH OH CH Dihydroxymandelic acid (DOMA) HO CH3O COOH OH CH 3-Methoxy-4-hydroxy￾mandelic acid (VMA)* CH3O HO CH2 NHCH3 OH CH Metanephrine HO CH2 NH2 OH CH Normetanephrine (NMN) CH3O HO HO COOH CH2 Dihydroxyphenylacetic acid (DOPAC) CH3O HO CH2 NH2 CH2 3-Methoxytyramine CH3O HO COOH CH2 Homovanillic acid (HVA) COMT COMT COMT COMT COMT MAO MAO MAO MAO MAO MAO PNMT DBH Adrenal medulla COMT = catechol-O-methyltransferase MAO = monoamine oxidase *Diagnosis of pheochromocytoma ( - ) Pargyline, Nialamide Pre-synaptic Post-synaptic Ca2+ Na+ Tyrosine Cellular messengers and effects Diffusion, metabolism Tyrosine Dopa TH DD Dopamine (DA) NE DBH ATP Ca2+ NE DBH ATP NE NE COMT Normetanephrine (NMN) αR βR α2R NE (-) Signal MAO: associated with outer surface of mitochondia, including those within the terminals of adrenergic fibers. COMT: located mostly in cytoplasm. Rich in liver, kidney; not found in adrenergic neurons. VMA: vanillylmandelic acid (3-Methoxy-4-hydroxymandelic acid)