katekolamiinid

Katekolamiinid, known in English as catecholamines, are a group of naturally occurring organic compounds derived from the amino acid tyrosine. These biogenic amines function as important neurotransmitters and hormones within the nervous system and endocrine system. The primary catecholamines include dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline).

Dopamine acts as a neurotransmitter in the brain, playing a crucial role in regulating mood, motivation, reward, and motor control. It is also a precursor in the synthesis of norepinephrine and epinephrine. Norepinephrine functions both as a neurotransmitter and a hormone, involved in the body's fight-or-flight response, regulating alertness, blood pressure, and heart rate. Epinephrine, produced mainly in the adrenal medulla, is released into the bloodstream during stressful situations, promoting physiological responses such as increased heart rate, dilation of airways, and energy mobilization.

Catecholamines are synthesized in neurons and adrenal medulla through a series of enzymatic reactions starting from tyrosine. They are stored in vesicles and released upon nerve stimulation or stress.

These compounds exert their effects primarily via adrenergic and dopaminergic receptors, which are G protein-coupled receptors distributed throughout the body. Imbalances or dysregulation of catecholamines have been associated with various medical conditions, including depression, schizophrenia, Parkinson's disease, and cardiovascular disorders.

In clinical practice, catecholamine levels are often measured to diagnose or monitor certain conditions, and pharmacological agents targeting their receptors are used in treating cardiovascular diseases, shock, and psychiatric disorders. Their critical role in physiology and medicine underscores the importance of catecholamines in maintaining homeostasis and responding to stress.