What is the Difference Between Epinephrine and Norepinephrine?

🆚 Go to Comparative Table 🆚

Epinephrine and norepinephrine are both hormones and neurotransmitters that play a role in the body's stress response and are part of a class of compounds known as catecholamines. They have similar chemical structures but produce different effects on the body. Here are the main differences between epinephrine and norepinephrine:

  1. Release: Norepinephrine is continuously released into circulation at low levels, while epinephrine is only released during times of stress.
  2. Effects on Heart and Blood Vessels: Epinephrine has a slightly greater effect on the heart, while norepinephrine has a more significant effect on blood vessels.
  3. Receptor Stimulation: Both epinephrine and norepinephrine work on alpha and beta receptors, but epinephrine has a greater effect on beta receptors compared to norepinephrine. Alpha receptors are only found in the arteries, while beta receptors are in the heart, lungs, and arteries of skeletal muscles.
  4. Chemical Names: Epinephrine is also known as adrenaline, while norepinephrine is sometimes referred to as noradrenaline.

Both epinephrine and norepinephrine play a role in the regulation of the sympathetic nervous system, which is responsible for the body's "fight or flight" response. They are also involved in medications for cardiovascular problems. Too much or too little of either compound can have noticeable effects on health, including anxiety, depression, fibromyalgia, hypoglycemia, migraine, restless legs syndrome, and sleep disorders.

Comparative Table: Epinephrine vs Norepinephrine

Epinephrine and norepinephrine are both hormones and neurotransmitters that play a role in the body's stress response. They belong to a class of compounds known as catecholamines and have similar chemical structures. However, they produce different effects on the body. Here is a table comparing the differences between epinephrine and norepinephrine:

Feature Epinephrine Norepinephrine
Alternative Name Adrenaline Noradrenaline
Effect on Heart Increases heart rate and contractility Increases heart rate, has less effect on contractility
Effect on Blood Vessels Dilates blood vessels Causes blood vessels to narrow, increasing blood pressure
Effect on Blood Sugar Increases blood sugar levels Increases blood sugar levels
Produced in Adrenal glands Nerves and adrenal medulla
Released During Times of stress Continuously at low levels
Receptors Greater effect on beta receptors Mainly acts on alpha receptors, stimulates beta receptors to a certain degree

Both epinephrine and norepinephrine play a role in the regulation of the sympathetic nervous system, which is responsible for the body's "fight or flight" response. They work on alpha and beta receptors, but epinephrine has a greater effect on beta receptors compared to norepinephrine.