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::Catecholamine

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norepinephrine (noradrenaline)
epinephrine (adrenaline)

A catecholamine (CA) is a monoamine, an organic compound that has a catechol (benzene with two hydroxyl side groups) and a side-chain amine.<ref>{{#invoke:citation/CS1|citation |CitationClass=book }}</ref>

Catechol is a chemical, but a catechol may also be used as the name of a substituent, where it represents a 1,2-dihydroxybenzene group.

Catecholamines are derived from the amino acid tyrosine.<ref name="Purves">{{#invoke:citation/CS1|citation |CitationClass=book }}</ref> Catecholamines are water-soluble and are 50%-bound to plasma proteins in circulation.

Included among catecholamines are: epinephrine (adrenaline), norepinephrine (noradrenaline) and dopamine; all of which are produced from phenylalanine and tyrosine. Release of the hormones epinephrine and norepinephrine from the adrenal medulla of the adrenal glands is part of the fight-or-flight response.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

Tyrosine is created from phenylalanine by hydroxylation by the enzyme phenylalanine hydroxylase. Tyrosine is also ingested directly from dietary protein. Catecholamine-secreting cells use several reactions to convert tyrosine serially to L-DOPA and then to dopamine. Depending on the cell type, dopamine may be further converted to norepinephrine or even further converted to epinephrine.<ref>{{#invoke:Citation/CS1|citation |CitationClass=journal }}</ref>

Various stimulant drugs are catecholamine analogues.


Catecholamine sections
Intro  Structure  Production and degradation  Function  See also  References  External links  

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