Figure 16-9 Biosynthesis of norepinephrine and epinephrine in sympathetic nerve terminal (and adrenal medulla). A, Perspective view of molecules. B, Enzymatic processes. (From Tollenaeré JP: Atlas of the Three-Dimensional Structure of Drugs. Amsterdam, Elsevier North-Holland, 1979 as modified by Vanhoutte PM: Adrenergic neuroeffector interaction in the blood vessel wall. Fed Proc 37:181, 1978.)