A comparison was made of the ultrastructure of two neurohemal organs: the sinus gland and the lateral nervous plexus of the Oniscidea (Crustacea). Reverse-phase chromatography clearly showed that the two organs contain different neuropeptides. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry proved to be an efficient tool for detecting the molecules stored in a single freshly dissected neurohemal organ. All the results combined lead us to emphasize that the sinus gland of Oniscidea stores mainly crustacean hyperglycemic hormone (CHH) and vitellogenin-inhibiting hormone; these two hormones were not characterized in the lateral nervous plexus (LNP). Smaller peptides and other molecules of the CHH family might be released by the LNP in the vicinity of the Y-organ (the ecdysteroid-producing gland).
