epinephrine

[ep-uh-nef-rin, -reen]
noun
1.
Biochemistry. a hormone secreted by the adrenal medulla upon stimulation by the central nervous system in response to stress, as anger or fear, and acting to increase heart rate, blood pressure, cardiac output, and carbohydrate metabolism.
2.
Pharmacology. a commercial form of this substance, extracted from the adrenal glands of sheep and cattle, or synthesized: used chiefly as a heart stimulant, to constrict the blood vessels, and to relax the bronchi in asthma.
Also, epinephrin.
Also called adrenaline.


Origin:
1895–1900; epi- + Greek nephr(ós) kidney + -ine2

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Collins
World English Dictionary
epinephrine or epinephrin (ˌɛpɪˈnɛfrɪn, -riːn)
 
n
a US name for adrenaline
 
[C19: from epi- + nephro- + -ine²]
 
epinephrin or epinephrin
 
n
 
[C19: from epi- + nephro- + -ine²]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Etymonline
Word Origin & History

epinephrine
1889, from epi- upon + nephros kidney + chemical suffix -ine.
Online Etymology Dictionary, © 2010 Douglas Harper
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American Heritage
Medical Dictionary

epinephrine ep·i·neph·rine or ep·i·neph·rin (ěp'ə-něf'rĭn)
n.

  1. A catecholamine hormone of the adrenal medulla that is the most potent stimulant of the sympathetic nervous system, resulting in increased heart rate and force of contraction, vasoconstriction or vasodilation, relaxation of bronchiolar and intestinal smooth muscle, glycogenolysis, lipolysis, and other metabolic effects. Also called adrenaline.

  2. A white to brownish crystalline compound isolated from the adrenal glands of certain mammals or synthesized and used in medicine as a heart stimulant, vasoconstrictor, and bronchial relaxant.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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American Heritage
Science Dictionary
epinephrine   (ěp'ə-něf'rĭn)  Pronunciation Key 
A hormone that is secreted by the adrenal gland in response to physical or mental stress, as from fear, and is regulated by the autonomic nervous system. The release of epinephrine causes an increase in heart rate, blood pressure, and respiratory rate. Epinephrine also raises glucose levels in the blood for use as fuel when more alertness or greater physical effort is needed. Also called adrenaline. Chemical formula: C9H13NO3.
The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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Encyclopedia Britannica
Encyclopedia

epinephrine

two separate but related hormones secreted by the medulla of the adrenal glands. They are also produced at the ends of sympathetic nerve fibres, where they serve as chemical mediators for conveying the nerve impulses to effector organs. Chemically, the two compounds differ only slightly; and they exert similar pharmacological actions, which resemble the effects of stimulation of the sympathetic nervous system. They are, therefore, classified as sympathomimetic agents. The active secretion of the adrenal medulla contains approximately 80 percent epinephrine and 20 percent norepinephrine; but this proportion is reversed in the sympathetic nerves, which contain predominantly norepinephrine.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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Example sentences
The medication needed to stop the allergic reaction in its tracks is
  epinephrine.
Adrenergic receptors are receptors which bind the neurotransmitters epinephrine
  and norepinephrine.
Even the captive-raised cavies had higher levels of norepinephrine and
  epinephrine from the get-go.
It decreases blood pressure by blocking the action of epinephrine, a stress
  hormone, in the peripheral nervous system.
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