Catecholamines
Catecholamines are chemical compounds derived form the amino acid tyrosine. They are secreted into the bloodstream by the adrenal medulla and the postganglionic fibers of the sympathetic nervous system. There are three amine hormones that are classified as catecholamines: epinephrine, norepinephrine, and dopamine.
Catecholamine production is generally stimulates by stress caused by either physiological or environmental factors. Their effects are those that prepare the body for changes in physical activity, often referred to as the “fight or flight” response. Catecholamines cause an increase in heart rate, blood pressure, and blood-glucose levels.
The structure of catecholamines is distinct and is that of a benzene ring with two hydroxyl groups, an intermediate ethyl chain, and a terminal amine group. When secreted, catecholamines have a half life of approximately a few minutes.