Rate limiting enzyme in catecholamine biosynthesis is: (A) Tyrosine hydroxylase, (B) Dopa Decarboxylase, (C) Dopamine beta-hydroxylase (DBH), (D) Phenylethanolamine-N-Methyltransferase (PNMT)
Answer is A. Tyrosine Hydroxylase Is Rate-Limiting for Catecholamine BiosynthesisRef: Harper&;s Biochemistry; 30th edition; Chapter 41; The Diversity of the Endocrine System