Katekolaminürítés

Katekolaminürítés refers to the process of excreting catecholamines in the urine. Catecholamines are a group of hormones and neurotransmitters that include dopamine, norepinephrine, and epinephrine (adrenaline). These substances play crucial roles in the body's "fight or flight" response, regulating heart rate, blood pressure, metabolism, and other physiological functions.

Normally, catecholamines are produced in the adrenal glands and nerve endings, where they exert their effects. Once their action is complete, they are metabolized into inactive compounds, primarily by enzymes such as catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). These metabolites are then excreted from the body, predominantly through the kidneys into the urine.

Measuring catecholamine levels in urine can be a diagnostic tool. Elevated levels of specific catecholamines or their metabolites in urine can indicate the presence of certain medical conditions. The most common condition associated with significantly elevated urinary catecholamines is pheochromocytoma, a rare tumor of the adrenal gland that excessively produces these hormones. Neuroblastoma, a cancer of nerve cells that often affects children, can also lead to increased catecholamine excretion. Other conditions, such as certain cardiovascular diseases or stress-related disorders, might also be associated with altered urinary catecholamine levels, though typically to a lesser extent than in tumors.

Urine tests for catecholamines are typically performed on a 24-hour urine collection to account for fluctuations in hormone production throughout the day. The analysis measures the concentration of the parent catecholamines or their specific metabolites, such as homovanillic acid (HVA) and vanillylmandelic acid (VMA).