Norepinephrine (NE), also called norepinephrine (NA), is an organic chemical in the family of catecholamines that works in the brain and body as a hormone and a neurotransmitter. This substance that is predominantly released from the ends of sympathetic nerve fibers and that acts to increase the strength of the skeletal muscle contraction, the speed and force of contraction of the heart.
Functions of norepinephrine or norepinephrine
The actions of norepinephrine are vital for the fight or flight response, whereby the body prepares to react or withdraw from an acute threat.
Norepinephrine is similar to adrenaline. It works by narrowing the blood vessels and increasing blood pressure and blood glucose levels (sugar).
Norepinephrine is structurally classified as a catecholamine, which contains a catechol group (a benzene ring with two hydroxyl groups) attached to an amine group (which contains nitrogen). The addition of a methyl group to the norepinephrine amino group results in the formation of epinephrine, the other main mediator of the escape or escape response.
Compared to epinephrine, which is produced and stored primarily in the adrenal glands, norepinephrine is stored in small amounts in the adrenal tissue. Its main storage and release zone is the neurons of the sympathetic nervous system (a branch of the autonomic nervous system). Therefore, norepinephrine It works primarily as a neurotransmitter with some function as a hormone It is released into the bloodstream from the adrenal glands.
Norepinephrine or norepinephrine transmits information in the form of electrical impulses to different parts of the body. It is released through the adrenergic neurons of the Central Nervous System (CNS). It also exerts its function in the Autonomous Nervous System (SNA), generating the activation of our body in situations of anxiety.
Thus, one of the main functions of norepinephrine as a neurotransmitter is the stimulation of adrenaline production in the body, causing an increase in surveillance activity, facilitating attention and improving the ability to react to possible dangerous events.
Also known as one of the stress hormones, norepinephrine is released into the blood after being synthesized by the amino acid called tyrosine through the adrenal glands, located above the kidneys.
Norepinephrine exerts its effects by binding to the α and β adrenergic receptors (or adrenoceptors, named for their reaction to adrenal hormones) in different tissues. In the blood vessels, it triggers the vasoconstriction (narrowing of the blood vessels), which increases blood pressure. Norepinephrine further increases blood pressure as a result of its effects on the heart muscle, which increases the blood production of the heart.
Norepinephrine also acts to increase blood glucose levels and free fatty acid levels circulating It has also been shown that the substance modulates the function of certain types of immune cells.
Norepinephrine that diffuses from local nerve endings can act on adrenergic receptors at distant sites.
Medical uses of norepinephrine
Norepinephrine is used clinically as a means to maintain blood pressure in certain types of disorders (eg, septic shock or septicemia). It is also used to treat life-threatening low blood pressure (hypotension) that can occur with certain medical conditions or surgical procedures. This medicine is often used during CPR (cardiopulmonary resuscitation).
The Swedish physiologist Ulf von Euler identified norepinephrine in the mid-1940s; He received a part of the 1970 Nobel Prize in Physiology or Medicine for his discovery.
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Michael W. King Biochemistry of neurotransmitters and nerve transmission: catecholamines. Indiana University School of Medicine