|Systematic (IUPAC) name|
|Half-life||15 Minutes in insects. Theorized to be longer in vertebrates.|
|Synonyms||Norsympathol, Norsynephrine, para-Octopamine, beta-Hydroxytyramine, para-hydroxy-phenyl-ethanolamine|
|Mol. mass||153.178 g/mol|
Octopamine (β,4-dihydroxyphenethylamine) is an endogenous biogenic amine that is closely related to norepinephrine, and has effects on the adrenergic and dopaminergic systems. It is also found naturally in numerous plants, including bitter orange. Biosynthesis of the D-(–)-enantiomer of octopamine is by β-hydroxylation of tyramine via the enzyme dopamine β-hydroxylase. Under the trade names Epirenor, Norden, and Norfen, octopamine is also used clinically as a sympathomimetic agent.
Role in invertebrates
Octopamine was first discovered by Italian scientist Vittorio Erspamer in 1948 in the salivary glands of the octopus and has since been found to act as a neurotransmitter, neurohormone and neuromodulator in invertebrates. Although Erspamer discovered its natural occurrence and named it, octopamine had actually existed for many years as a pharmaceutical product. It is widely used in energy-demanding behaviors by all insects, crustaceans (crabs, lobsters, crayfish), and spiders. Such behaviors include flying, egg-laying, and jumping.
Octopamine acts as the insect equivalent of norepinephrine and has been implicated in regulating aggression in invertebrates, with different effects on different species. Studies have shown that reducing the neurotransmitter octopamine and preventing coding of tyramine beta hydroxylase (an enzyme that converts tyramine to octopamine) decreases aggression in Drosophila without influencing other behaviors.
The best-understood role for octopamine is in the locust jump. Here it modulates muscle activity, making the leg muscles contract more effectively. This is at least in part due to an increase in the rate of contraction and of relaxation.
Octopamine also plays a role in snail.
In lobsters, octopamine seems to direct and coordinate neurohormones to some extent in the central nervous system, and it was observed that injecting octopamine into a lobster and crayfish resulted in limb and abdomen extension.
The emerald cockroach wasp stings the host for its larvae (a cockroach) in the head ganglion (brain). The venom blocks octopamine receptors and the cockroach fails to show normal escape responses, grooming itself excessively. It becomes docile and the wasp leads it to the wasp's den by pulling its antenna like a leash.
Role in vertebrates
In vertebrates, octopamine replaces norepinephrine in sympathetic neurons with chronic use of monoamine oxidase inhibitors. It may be responsible for the common side effect of orthostatic hypotension with these agents, though there is also evidence that it is actually mediated by increased levels of N-acetylserotonin.
One study noted that octopamine might be an important amine that influences the therapeutic effects of inhibitors such as monoamine oxidase inhibitors, especially because a large increase in octopamine levels was observed when animals were treated with this inhibitor. Octopamine was positively identified in the urine samples of mammals such as humans, rats, and rabbits treated with monoamine oxidase inhibitors. Very small amounts of octopamine were also found in certain animal tissues. It was observed that within a rabbit's body, the heart and kidney held the highest concentrations of octopamine.
In mammals, octopamine may mobilize the release of fat from adipocytes (fat cells), which has led to its promotion on the internet as a slimming aid. However, the released fat is likely to be promptly taken up into other cells, and there is no evidence that octopamine facilitates weight loss. Octopamine may also increase blood pressure significantly when combined with other stimulants, as in some weight loss supplements.
Owing to lack of research, much is not known about octopamine or its role in humans.
- Tang, F; Tao, L; Luo, X; Ding, L; Guo, M; Nie, L; Yao, S (2006). "Determination of octopamine, synephrine and tyramine in Citrus herbs by ionic liquid improved 'green' chromatography". Journal of chromatography. A 1125 (2): 182–8.
- Jagiełło-Wójtowicz E (1979). "Mechanism of central action of octopamine". Pol J Pharmacol Pharm 31 (5): 509–16.
- Swiss Pharmaceutical Society (2000). Index Nominum 2000: International Drug Directory (Book with CD-ROM). Boca Raton: Medpharm Scientific Publishers.
- Pharmacognosy And Pharmacobiotechnology - Google Books.
- Erspamer, V., Active substances in the posterior salivary glands of Octopoda. 2. Tyramine and octopamine (oxyoctopamine) (1948). "Active Substances in the Posterior Salivary Glands of Octopoda. II. Tyramine and Octopamine (Oxyoctopamine)". Acta Pharmacologica et Toxicologica 4 (3–4): 224–247.
- Kakimoto, Yasuo; Marvin Armstrong (February 1962). "On the Identification of Octopamine in Mammals". The Journal of Biological Chemistry 237: 422–427.
- Zhou, Chuan; Yong Rao,
- Livingstone, Margaret; Ronald Harris-Warrick; Edward Kravitz (4 April 1980). "Serotonin and Octopamine Produce Opposite Postures in Lobsters". Science 208 (4439): 76–79.
- Heberlein, U.; Wolf, FW; Rothenfluh, A; Guarnieri, DJ (2004). "Molecular Genetic Analysis of Ethanol Intoxication in Drosophila melanogaster". Integrative and Comparative Biology 44 (4): 269–74.
- Moore, M. S., Dezazzo, J., Luk, A. Y., Tully, T., Singh, C. M., and Heberlein, U. (1998). "Ethanol intoxication in Drosophila: Genetic and pharmacological evidence for regulation by the cAMP pathway". Cell 93 (6): 997–1007.
- Tecott, L. H. and Heberlein, U. (1998). "Y do we drink?". Cell 95 (6): 733–735.
- Bar Flies: What our insect relatives can teach us about alcohol tolerance., Ruth Williams, Naked Scientist
- ‘Hangover gene’ is key to alcohol tolerance, Gaia Vince, NewScientist.com news service, 22 August 2005
- How to make a zombie cockroach, Nature News, 29 September 2007
- Gal, Ram; Rosenberg, Lior Ann; Libersat, Frederic (22 November 2005). "Parasitoid wasp uses a venom cocktail injected into the brain to manipulate the behavior and metabolism of its cockroach prey". Archives of Insect Biochemistry and Physiology 60 (4): 198–208.
- Minerd, Jeff (12 September 2005). "Ephedra-Free Supplements Not Necessarily Risk-Free". MedPage Today. Retrieved 12 September 2009.
- Haller, C; Benowitz, N; Jacobiii, P (2005). "Hemodynamic effects of ephedra-free weight-loss supplements in humans". The American Journal of Medicine 118 (9): 998–1003.
- P.D. Evans, "Octopamine", in Comprehensive Insect Physiology, 11, 499, Oxford University Press 1985.