Norepinephrine, adrenalin, and dopamine are known as catecholamines, as they contain a catechol moiety, an amine side-chain and they are all derived from the amino acid tyrosine.
Norepinephrine is synthesized from dopamine-by-dopamine β-hydroxylase. It is released from the adrenal medulla into the blood as a hormone, and is also a neurotransmitter in the central nervous system and sympathetic nervous system where it is released from noradrenergic neurons.
In 1947 Ulf von Euler was the first to show that norepinephrine was the main neurotransmitter in the sympathetic nervous system.
In human body, norepinephrine is found in the peripheral and central nervous system, where it regulates a numerous assortment of physiological processes that include mood, arousal, learning and memory, blood flow, and metabolism,
As a stress hormone, norepinephrine affects parts of the brain where attention and responding actions are controlled. Along with epinephrine, norepinephrine also underlies the fight-or-flight response, directly increasing heart rate, triggering the release of glucose from energy stores, and increasing blood flow to skeletal muscle.
What is norepinephrine?
