Octopamine is a naturally occurring selective beta-3 adrenergic receptor agonist, and has been shown in studies to exhibit strong lipolytic activity in fat cells. It is also the first selective beta-3 agonist ever to be isolated and made available as a nutritional supplement that has the ability to mediate human fat loss and works as a powerful, comfortable and safe fat-loss alternative to a non-selective beta agonist like ephedrine.
Octopamine is a trace amine, a class of molecules that naturally occur in both vertebrate and invertebrate species. Octopamine was first identified 50 years ago in the octopus, and while the biological role it plays in many invertebrate species is well established, the physiological role octopamine plays in mammals is not well known. Octopamine is derived from tyramine, another trace amine that is derived from tyrosine or from tyramine-containing food. Octopamine can also be further metabolized into synephrine via the enzyme pheylethanolamine N-methyltransferase. In invertebrates, the role of octopamine is analogous to that of norepinephrine (NE) in vertebrates, and it is responsible for the "fight or flight" effect and fat mobilizing.
Octopamine is a major neuromodulator with neurotransmitter and neurohormone functions that mediates diverse physiological processes in the peripheral nervous system and CNS of invertebrates. Examples of potential functions include feeding behavior in blowflies and honeybees, light production in the firefly lantern, carbohydrate and fatty acid metabolism in locusts, escape behavior in crayfish, and complex behaviors such as conditioned courtship and olfactory learning in Drosophila. These invertebrate behaviors probably occur through the activation of an octopamine receptor, specifically the octopamine receptor coupled to the activation of the enzyme adenyl cyclase and the synthesis of cyclic AMP (cAMP) and intracellular Ca+2 ([Ca+2]i).
The octopamine receptor disclosed, octopamine receptor in mushroom bodies (OAMB), is highly enriched in the mushroom bodies of Drosophila and stimulates cAMP and [Ca+2]i accumulation upon octopamine application. Although this receptor was heavily sought after by many groups, previous attempts to clone it had been unsuccessful. From the DNA sequence of OAMB, a protein of 637 amino acids is predicted with seven hydrophobic domains highly similar to the transmembrane domains of G-protein-coupled receptors (GPR). From the sequence similarity it is deduced that OAMB belongs to the biogenic amine receptor superfamily.