monoaminy

Monoaminy, also known as monoamines, are a class of organic compounds that contain a single amine group attached to a carbon skeleton. They are typically weak bases, form salts with acids, and can be primary, secondary, or tertiary amines depending on the number of carbon substituents on the nitrogen. In physiological contexts, monoamines are often polar and exist in protonated forms under biological pH.

Biologically important monoamines include dopamine, norepinephrine, and serotonin, which are collectively referred to as monoamine neurotransmitters. Histamine is another widely studied monoamine involved in immune responses and gastric acid secretion. Monoamines are classified into subgroups such as catecholamines (dopamine, norepinephrine, epinephrine) and indoleamines (serotonin), based on their chemical structures. They are typically derived from amino acids: dopamine, norepinephrine, and epinephrine from tyrosine, serotonin from tryptophan, and histamine from histidine, through a series of enzymatic steps including decarboxylation and, in some cases, hydroxylation or methylation.

In the nervous system, monoamines regulate mood, arousal, attention, autonomic function, and other central and peripheral processes. Signaling is terminated primarily by reuptake into presynaptic neurons via specific transporters (such as DAT, NET, and SERT) and by enzymatic degradation through monoamine oxidases (MAO) and catechol-O-methyltransferase (COMT). Pharmacologically, monoamine systems are targets for a range of drugs, including antidepressants, antipsychotics, and agents that modulate sympathetic activity. Dysregulation of monoaminergic signaling is linked to conditions such as depression, anxiety disorders, Parkinson’s disease, and schizophrenia.