Octopamine, unlike other trace amines, inhibits responses of astroglia-enriched cultures to lipopolysaccharide via a I2-adrenoreceptor-mediated mechanism

• Published in: Neuroscience letters 2012-05, Vol.517 (1), p.36-40
• Main Authors: DaAndrea, Giovanni, DaArrigo, Antonello, Facchinetti, Fabrizio, Del Giudice, Elda, Colavito, Davide, Bernardini, Daniele, Leon, Alberta
• Format: Article
• Language: English
• Subjects: amines; Antagonists; Astrocytes; Catecholamines; Cell culture; Data processing; Headache; Lipopolysaccharides; Migraine; Nervous system; Neuromodulation; Nitric oxide; octopamine; Structure-function relationships; Sympathomimetics; tyramine
• ISSN: 0304-3940
• DOI: 10.1016/j.neulet.2012.04.013

Trace amines (TAs), i.e. I2-phenylethylamine, tyramine and octopamine, are generally regarded as sympathomimetic compounds with structural and functional analogy with catecholamines. Previous reports have shown particularly high levels of circulating TAs in migraine and cluster headache patients. However, no clues are yet available as to the pathophysiological significance of these alterations. The effect of different TAs on the release of nitric oxide was investigated in rat astroglial cells stimulated with lipopolysaccharide (LPS). Octopamine substantially inhibited the release of NO evoked by LPS. Tyramine and I2-PEA were ineffective. The inhibitory effect of octopamine was fully reverted by two selective antagonists of I2-adrenergic receptors, while [alpha]-adrenergic blockade was ineffective. These data, consistent with a role of octopamine as a modulator of NO release, uncover an interaction between octopamine and I2-adrenergic receptors in astroglial cells. These results may have an impact in understanding the mechanisms underlying migraine pathophysiology.