Conversion of norepinephrine to epinephrine occur by

Synthesis of NA occurs in all adrenergic neurons while that of adrenaline occurs only in the adrenal medullary cells. It requires a high concentration of glucocoicoids reaching through the intra- adrenal poal circulation for induction of the methylating enzyme - N methyltransferase. From essential of medical pharmacology K D Tripati 7th edition Page no 124