Julius Axelrod (Nobel Laureate,1970) His discoveries concern the mechanisms which regulate the formation of norepinephrine in the nerve cells and the mechanisms which are involved in the inactivation of this important neurotransmitter. Synthesis of Catecholamines Tyrosine hydroxylase Phenylethanolamine- N-methyl transferase Dopa decarboxylase (L-amino acid 0\ (L-AAD decarboxylase) Adrenal medulla Dopamine B-hydroxylase Regulation of Norepinephrine Synthesis and Metabolism: Uak1 E 的 Post-synaptic Pre-synaptic Ca NENE ● Diffusion, Normetanephrine(NMN) metabolism 77 HO HO CH2 NHCH3 OH CH Epinephrine HO HO CH2 NH2 OH CH Norepinephrine HO HO CH2 NH2 CH2 Dopamine HO HO HC NH2 CH2 DOPA COOH HO HC NH2 CH2 Tyrosine COOH TH DD (L-AAD) PNMT DBH Adrenal medulla Synthesis of Catecholamines Tyrosine hydroxylase Dopa decarboxylase (L-amino acid decarboxylase) Dopamine β-hydroxylase Phenylethanolamine￾N-methyl transferase 1 3 Julius Axelrod (Nobel Laureate, 1970) His discoveries concern the mechanisms which regulate the formation of norepinephrine in the nerve cells and the mechanisms which are involved in the inactivation of this important neurotransmitter. 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 αR βR α2R NE (-) Signal Regulation of Norepinephrine Synthesis and Metabolism: Uptake-1 Normetanephrine (NMN)