The Unique Neuropeptide Pattern in Abdominal Perisympathetic Organs of Insects

: We successfully isolated and identified the abundant neuropeptides of the abdominal perisympathetic organs of the American cockroach, including all myoactive compounds. Peptide sequence analysis and mass spectrometry of abundant substances that were not bioactive in different muscle assays yielded the following sequences: TDPLWQLPGAHLEQYLS‐NH2 (Pea‐YLSamide), AFLTLTPGSHVDSYVEA‐OH (Pea‐VEAacid), and SDLTW‐TYQSPGDPTNSKN‐OH (Pea‐SKNacid). The given structures led to the conclusion of an unique neuropeptide pattern in abdominal perisympathetic organs. We confirmed this assumption with immunocytochemical studies, using antisera raised against different myotropic neuropeptides of the abdominal perisympathetic organs. Moreover, mass spectrometric methods, developed for the investigation of single neurohemal organs, confirmed the neuropeptide pattern in these organs.