Phenylethylamine and tyramine are mixed-acting sympathomimetic amines in the brain.

Knoll J, Miklya I, Knoll B, Marko R, Racz D.

Department of Pharmacology
Semmelweis University of Medicine
Budapest, Hungary.
Life Sci 1996;58(23):2101-14

On the helical strip of a capacitance vessel, the pulmonary artery of the rabbit, phenylethylamine (PEA) and tyramine act solely via displacement of noradrenaline from their storage sites and this effect is inhibited by desmethylimipramine (DMI).  In contrast, on a resistance vessel, the perfused central ear artery of the rabbit, PEA enhances stimulation induced contractions in 0.2-0.8 microgram/ml concentration [catecholaminergic activity enhancer (CAE) effect], and increases smooth muscle tone (noradrenaline displacing effect) in 4-6 micrograms/ml concentration. This latter effect only is blocked by DMI. Tyramine acts similarly and is more potent than PEA.  On the isolated brain stem PEA, tyramine and (-)methamphetamine are, in the presence of cocaine and DMI, highly potent enhancers of stimulation induced release of 3H-noradrenaline, 3H-dopamine and 3H-serotonin.  Compounds with specific CAE effect in the brain, (-)deprenyl and 1-phenyl-2-propylaminopentane [(-)PPAP], antagonize tetrabenazine-induced depression of performance of rats in the shuttle box.  PEA and tyramine, which are rapidly metabolized in vivo, are ineffective in this test up to 40 mg/kg, whereas (-)methamphetamine, the stable PEA derivative, is highly effective.  Compounds with CAE effect enhance at low concentrations the slow inward Ca2+ current in the sino-auricular fibers of the frog heart and inhibit it in high concentration.  PEA and tyramine enhance Ca2+ influx from 0.05 to 4 micrograms/ml and inhibit it in 8 micrograms/ml. In conclusion, PEA and tyramine stimulate primarily coupling of action potential to transmitter release in the catecholaminergic neurons in the brain and displace catecholamines in higher concentration only.

International Antiaging Systems
Les Autelets  Suite A
Sark  GY9 0SF
Channel Islands
Great Britain
phone: 44-870-151-4144 (Britain)
contact us
   we do not accept telephone orders
  we do not ship to the United Kingdom

articles by James South
1.    Centrophenoxine the brain booster
2.    DHEA the next generation
3.    GHB the elixir of life
4.    Growth Hormone, the real fountain of youth
5.    Idebenone the ultimate anti-aging drug?
6.    James South's personal supplement regime
7.    Laetrile (B17) the answer to Cancer
8.    NADH the body and mind energizer
9.    Nootropics reviewing the smart drugs.
10.  Pregnenolone the role of the "happy" hormone
11.  Pyritinol the oldest smart drug?
12.  Resveratrol anti-heart, anti-cancer
13.  SAMe for mood, liver, heart, and brain protection
14.  Silver for internal and topical infections
15.  Thymus Gland: its vital but overlooked role.
16.  Tired of being tired?
17.  Tryptophan, nature’s answer to Prozac
18.  Vinpocetine superior cerebral enhancer and protector.
19.  Weight loss the anti-aging way 
20.  5-HTP Prozac's true alternative