Only the adrenal medulla contains all 4 enzymes necessary for the production of all catecholamines.Ģ enzymes are important for the degradation of catecholamines - monoamine oxidase (MAO)' and catechol-O-methyltransferase (COMT). However, it can be said that dopamine or norepinephrine is produced in neurons', while the main product of the adrenal medulla is adrenaline. The enzyme equipment of a certain cell (neuron or chromaffin cell of the adrenal medulla) is decisive for the production of the resulting catecholamine. The donor of the methyl group in the last reaction is S-adenosylmethionine (SAM), which is converted to S-adenosylhomocysteine by cleavage of the methyl. Finally, adrenaline is produced in the medulla of the adrenal glands by methylation of noradrenaline with the help of phenylethanolamine-N-methyltransferase' (PNMT).This reaction requires ascorbic acid, which acts as an oxygen-carrying coenzyme. Dopamine is hydroxylated in the adrenal medulla and in ``noradrenergic neurons by ``dopamine-β-hydroxylase to form noradrenaline. This is followed by decarboxylation to dopamine by the enzyme DOPA-decarboxylase' with the coenzyme pyridoxal phosphate, present in all tissues synthesizing catecholamines.

The initial substrate is tyrosine, which is hydroxylated in the presence of tetrahydrobiopterin and molecular oxygen by the enzyme tyrosine hydoxylase' to Template:L-DOPA' (3, 4-dihydroxyphenylalanine).These impulses lead to the secretion of acetylcholineu by the preganglionic neurons that innervate the adrenal medulla. The synthesis is induced by various stressful situations, when the adrenergic nuclei of the hypothalamus start sending out impulses.

Catecholamines adrenal medulla