Two types of neurotransmitters, epinephrine and norepinephrine, are involved in neural communication. The University of Washington says epinephrine, also called adrenaline, and norepinephrine belong to a neurotransmitter group called catecholamines. This group also includes dopamine. Although the body produces both of these chemicals naturally, doctors can use them for medical conditions as well.
Production
Epinephrine and norepinephrine have similarities chemically because they belong to the same neurotransmitter group. The University of Washington says the production of both neurotransmitters start with tyrosine, another neurotransmitter. The enzyme tyrosine hydroxylase changes tyrosine to L-Dopa. L-Dopa becomes dopamine through the actions of the enzyme dopa decarboxylase. The enzyme dopamine β-hydroxylase turns dopamine into norepinephrine. Norepinephrine can become epinephrine when the enzyme PNMT acts upon norepinephrine.
Inactivation
When the brain needs to use a neurotransmitter, it releases the chemical through the axon terminal. Receptors on the other side of the terminal accept the neurotransmitter, where the chemical becomes used. Once the brain uses the neurotransmitters and doesn't need it anymore, it deactivates it. The University of Washington says the deactivation method of epinephrine and norepinephrine is the reuptake method. During reuptake, the brain takes the whole neurotransmitter back up into the axon terminal. This process recycles the neurotransmitter so the brain can use it again.
History
Epinephrine and norepinephrine have different discoveries. W. Sneader, author of the Drug News and Perspectives article “The Discovery and Synthesis of Epinephrine,” noted that epinephrine was the first hormone isolated, which occurred in 1900 by Farbwerke Hoechst. Six years later, Hoechst produced synthetic epinephrine. C. George Boeree, Ph.D., at Shippensburg University added that Ulf von Euler discovered norepinephrine in 1946.
Effects on the Body
Each neurotransmitter has different effects on the body. For example, Boeree noted that norepinephrine affects the sympathetic nervous system, the nervous system involved in the fight-or-flight response during a stressful event. The sympathetic nervous system causes people's panic responses. As a result, norepinephrine causes increased heart rate and blood pressure. Norepinephrine has other functions, such as memory formation. Drugs.com adds that epinephrine causes blood vessels to narrow. The neurotransmitter also helps with breathing by opening up the airways.
Medical Purposes
Medications that contain these chemicals can treat certain medical conditions. An epinephrine injection can treat a severe allergic reaction. A norepinephrine injection treats severely low blood pressure. Drugs.com says a medical professional can use a norepinephrine injection during CPR. Other medications can target these neurotransmitters. For example, medications such as serotonin and norepinephrine reuptake inhibitors or norepinephrine and dopamine reuptake inhibitors increase norepinephrine levels, which helps with depression.
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