Octopamine neurohormone

Identified octopaminergic neurons belong to the unpaired median class. Peripherally, octopamine is associated with a broad range of tissues, including muscular, reproductive and lantern tissue. Octopamine functions as a neurotransmitter, neurohormone and neuromodulator in insects, and octopamine has been proposed as the mediator of a sympathomimetic response. 

These peptidergic hormones then result in the sustained output of lipid from the fat body. Octopamine thus serves a role as a neurotransmitter controlling release of peptidergic AKHs and a neurohormone acting directly upon the fat body during flight in locusts. It is now apparent that octopamine may also mediate the release of other peptides from the corpus cardicaum (63-65). 

The biogenic amine octopamine (OA) is widely recognized as an important neuroregulator in many invertebrates. It has been proposed as a neurotransmitter in the firefly light organ, and as a neuromodulator of muscle action and a neurohormone in the locust (J, 2). Octopamine also appears to act on central nervous system (CNS) sites affecting coordinated motor actions (3,4), and has been shown to modulate CNS thresholds for feeding in blowflies (5), and olfaction in honeybees (6). 

Orchard, I. 1982. Octopamine in insects neurotransmitter, neurohormone, and neuromodulator. Can. J. Zool. 60 659-669. 

In the transformation of biogenic amines to other biologically active products, a number of different oxygenases, methyltrans-ferases and other enzymes take part (Figure 10.17). Oxidation of tyramine yields 4-(2-amino-l-hydroxyethyl)phenol, known as octopamine, first demonstrated in Octopus species, which acts as a neurohormone and neuromodulator in invertebrates. Methylation... 

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