Epinephrine

Epinephrine is a signal that energy is needed immediately. It stimulates breakdown of glycogen, fat, and protein. 

Epinephrine, a hormone made in the adrenal medulla and sympathetic nerve endings, calls for rapid mohilization of energy and glucose. Epinephrine, like glucagon, hinds to specific cellular receptors and activates adenylate cyclase. For the most part, epinephrine can he considered 

Campbell, Mary K. (1999). Biochemistry, 3rd edition. New York Saunders. 

Donald, and Voet, Judith G. (1995). Biochemistry, 2nd edition. New York Wiley. 

The neurotransmitter action of epinephrine is terminated by reuptake into the neuron that released it, or breakdown to inactive metabolites by the enzymes catechol-O-methyl transferase (COMT) and monoamine oxidase (MAO). The second messenger effects inside the cell are terminated by enzymes that break down cAMP, and by phosphatases that reverse the action of the kinases by removing phosphates. 

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Epinephrine is also known as adrenaline and is a hormone with profound physiological effects designed to prepare the body for fight or flight... 

Several naturally occurring amines mediate the transmission of nerve impulses and are referred to as neurotransmitters Two examples are epinephrine... 

Most of the drugs such as epinephrine and albuterol used to treat asthma attacks are bronchodilators—substances that expand the bronchial passages Newer drugs are designed to either inhibit the enzyme 5 lipoxygenase which acts on arachidomc acid m the first stage of leukotriene biosynthesis or to block leukotriene receptors... 

Fig. 2. Chemical stmcture of the endogenous catecholamines, epinephrine (8), and norepinephrine (7), and several synthetic phenethano1 amines that alter...

Histamine in the Cardiovascular System. It has been known for many years that histamine is present in sympathetic nerves and has a distribution within the heart that parallels that of norepinephrine (see Epinephrine and norepinephrine). A physiological role for cardiac histamine as a modulator of sympathetic responses is highly plausible (15). A pool of histamine in rat heart located neither in mast cells nor in sympathetic nerves has been demonstrated. The turnover of this metaboHcaHy active pool of histamine appears to be maintained by normal sympathetic activity. 

Amino acid-derived hormones include the catecholamines, epinephrine and norepinephrine (qv), and the thyroid hormones, thyroxine and triiodothyronine (see Thyroid AND ANTITHYROID PREPARATIONS). Catecholamines are synthesized from the amino acid tyrosine by a series of enzymatic reactions that include hydroxylations, decarboxylations, and methylations. Thyroid hormones also are derived from tyrosine iodination of the tyrosine residues on a large protein backbone results in the production of active hormone. 

Detoxifica.tlon. Detoxification systems in the human body often involve reactions that utilize sulfur-containing compounds. For example, reactions in which sulfate esters of potentially toxic compounds are formed, rendering these less toxic or nontoxic, are common as are acetylation reactions involving acetyl—SCoA (45). Another important compound is. Vadenosylmethionine [29908-03-0] (SAM), the active form of methionine. SAM acts as a methylating agent, eg, in detoxification reactions such as the methylation of pyridine derivatives, and in the formation of choline (qv), creatine [60-27-5] carnitine [461-06-3] and epinephrine [329-65-7] (50). 

Catecholamines. The catecholamines, epinephrine (EPl adrenaline) (85), norepinephrine (NE noradrenaline) (86) (see Epinephrine and norepinephrine), and dopamine (DA) (2), are produced from tyrosine by the sequential formation of L-dopa, DA, NE, and finally EPl. EPl and NE produce their physiological effects via CC- and -adrenoceptors, a-Adrenoceptors can be further divided into CC - and a2-subtypes which in turn are divided... 

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