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norepinephine and epinephine?


What is the difference betweeen norepinephrine and epinephine?


a search on google should give you an answer in about a minute or so.


epinephrine attaches to beta 2 adrenoceptors better than norepinephrine.


The structure is the exact same for each except epinephrine has a (H-N-CH3) molecule instead of the (NH2) molecule that norepinephrine has.

Norepinephrine is a precursor of epinephrine. 80% of adrenal medulla secretions are in the form of epinephrine. The major neurotransmitter released from the sympathetic nervouse system is norepinephrine.

A primary function of epinephrine is to stimulare glycogenesis in the liver and active muscle and lipolysis in adipose tissue and active muscle; norepinephrine is a powerful stimulator of lipolysis in adipose tissue.

They basically do the same thing. Hope this helps.


If anyone cares, I came across another tidbit of knowledge while reading...

Epinephrine (adrenaline) stimulates heart rate.

Norepinephrine (noradrenaline) helps to maintain constant blood pressure.


Paul, they actually both stimulate heartrate and maintain blood pressure by vasostriction.


buy a physiology/endocrinology text book, you will love it!