Dopamine Unit Converter

Dopamine is a catecholamine neurotransmitter that plays essential roles in movement, motivation, mood, and cardiovascular regulation. It is part of the catecholamine family alongside norepinephrine and epinephrine.

A plasma dopamine test measures the small amount of free (unconjugated) dopamine circulating in the blood. Only about 2% of plasma dopamine circulates in this free form; the rest exists as inactive conjugates. It is typically ordered as part of a fractionated catecholamines panel.

Plasma dopamine provides a point-in-time snapshot and has a very short half-life of roughly two minutes, so levels are strongly influenced by posture, stress, and specimen handling.

Most plasma dopamine originates from sympathetic nerve endings, with smaller contributions from the adrenal medulla and kidneys. The gastrointestinal tract is the body's largest producer of dopamine overall, but the liver metabolises most of it before it reaches the bloodstream. Dopamine produced in the brain does not cross the blood-brain barrier and does not contribute to plasma levels.