Benelux Congress of Zoology edition:9 location:Antwerp, Belgium date:8-9 November 2002
Insects are, as mammals, complex multicellular organisms. For proper functioning of these organisms there has to be a form of communication between the cells building up this multicellular organism. For this communication they are equipped with a neural and a hormonal system. An important part of this dual system is the neuroendocrine system which consists of the hypothalamus-pituitary complex in mammals and its insect counterpart called the pars intercerebralis-corpus cardiacum complex. In these complexes there is a close collaboration between the neural and the hormonal system. We prefer Locusta migratoria as a model since a large number of neuropeptides present in the corpora cardiaca of this insect have already been identified and characterised (adipokinetic hormones, hypertrehalosaemic hormone, diuretic hormone, myotropins, pyrokinins,…). Our aim in this study is to determine the factors that are responsible for the release, or modulation of release, of these neuropeptides into the circulation. Released peptides are trapped on disposable seppak C18 columns and detected using a size exclusion column and conventional HPLC. The actual identification of these peptides occurs in a second chromatographic run combined with Electrospray Ionisation double Quadrupole Time Of Flight Mass Spectrometry (NanoLC-MS). After administration of melatonin to the tissue we were able, using this method, to identify seven peptides (Adipokinetic hormone Precursor Related Peptides 1 and 2, Neuroparsins A1, A2 and B, Insulin Related Peptide C Chain and Diuretic Peptide) in the melatonin induced chromatographic peak.