Wliich of the following is needed for conversion of norepinephrine to epinephrine:
High-Yield Explanation
Ans. (c) PENMTRef.:KDT 6th ed. /116* PENMT is Phenylethanolamine N- methyl transferase and is found in the cytosol of only cells of adrenal medullary cells.* PNMT uses S- adenosylmethionine (SAMe) as a cofactor to donate the methyl group to norepinephrine, creating epinephrine.* Epinephrine is synthesized in the medulla of the adrenal gland in an enzymatic pathway that converts the amino acid tyrosine into a series of intermediates and, ultimately, adrenaline.* Tyrosine is first oxidized to L-DOPA, which is subsequently decarboxylated to give dopamine. Oxidation gives norepinephrine.* The final step is methylation of the primary amine of noradrenaline by phenylethanolamine N-methyltransferase (PNMT) in the cytosol of adrenergic neurons and cells of the adrenal medulla (chromaffin cells).