What are Biogenic Amines?

     a biogenic amine is a substance with one or multiple amine groups. A majority of biogenic amines form via decarboxylation of amino acids, animation or transamination of aldehydes and ketones. Moreover, there are two divisions of biogenic amines within this experiment: catecholamines and indoleamines. For example, there are three catecholamine neurotransmitters: dopamine, norepinephrine, and epinephrine. As well as, indoleamines, including: tryptophan and serotonin. Furthermore, the catecholamines all arise from a common precursor, known as tyrosine. Firstly, in the synthesis of the catecholamines: the enzyme tyrosine hydroxylase synthesizes DOPA. Also, tyrosine hydroxylase is rate-limiting in relation to the synthesis of the three catecholamines. Additionally, the biosynthetic pathway of the catecholamines is: tyrosine→ DOPA → dopamine → norepinephrine → epinephrine along with multiple enzymes responsible for formation and degradation. For example, tyrosine hydroxylase, DOPA decarboxylase, dopamine beta hydroxylase, and PNMT. Whereas, the biosynthetic pathway for the indoleamines is tryptophan → 5-HTP → 5-HT → 5-hydroxyindoleacetic acid (5-HIAA). The enzymes utilized in this pathway are: tryptophan hydroxylase, amino acid decarboxylase, MAO, and aldehyde dehydrogenase. 

    Finally, it is important to recognize that many drugs of abuse will alter extracellular levels of these biogenic amines through direct and indirect interactions. For example, there are five drugs: alpha-methyl-para-tyrosine, cocaine, GBR 12935, haloperidol, and SCH 39166. Additionally, alpha-methyl-para-tyrosine depletes the neurotransmitter stores of dopamine and norepinephrine at the nerve terminal. For instance, AMPT is a compound that is an inhibitor of tyrosine hydroxylase. In other words, AMPT reduces the synthesis of dopamine and norepinephrine via tyrosine hydroxylase, basically inhibiting the conversion of tyrosine to DOPA (Gillin 1994). Whereas, cocaine increases levels of dopamine within the synapse. For example, this is done by preventing DAT from removing dopamine from the synapse. Thus, it increases the concentration and accumulation of dopamine levels within the synapse to produce an amplified signal to the receiving neuron (Sherman 2017). Similarly, GBR 12935 is a dopamine reuptake inhibitor. Whereas, haloperidol, “competitively blocks postsynaptic dopamine (D2) receptors” (DrugBank). Resulting in, the lack of dopamine neurotransmission commonly utilized in patients diagnosed with potential psychosis; the presence of excess postsynaptic dopamine activity. Finally, SCH 39166 is a selective dopamine (D1) receptor antagonist (Chipkin). Overall, the drug options seem to have significant involvement with the catecholamines. However, once the data collected from the brain tissue is analyzed, it is possible to reasonably judge and determine the relations of the drug and the concentration of the biogenic amines. Granting, the information needed to further the understanding of the functionality of biogenic amines.