Biochemistry

Tryptophan н 5-hydroxytryptophan Dopamine (DOPA). Nerve cells containing dopamine mediator are involved in the control of muscle movements. DOPA is a precursor to noradrenaline and adrenaline. Its source in the body is tyrosine, which, under the action of a specific hydrolase, turns into 3,4-dioxiphenylalanine (dopamine). Dopamine Histamine. This mediator dilates small vessels (arterioles and capillaries), regulates smooth muscle tone, and enhances secretion in the stomach. Histamine is formed from the amino acid histidine with the participation of vitamin B 6 . CH r CH 2 “ NH 2 N ----- H H-COOH Histidine Histamine 280