ISOLATION OF PERIVISCEROKININ-2 FROM THE ABDOMINAL PERISYMPATHETIC ORGANS OF THE AMERICAN COCKROACH, PERIPLANETA-AMERICANA

Using the isolated hyperneural muscle as bioassay, a novel myotropin w as isolated from the abdominal perisympathetic organs of Periplaneta a mericana. This is the second neuropeptide identified from insect peris ympathetic organs. Peptide sequence analysis and mass spectrometry yie lded the following structure: y-Ser-Ser-Ser-Gly-Leu-Ile-Ser-Met-Pro-Ar g-Val-NH2. This peptide, named periviscerokinin-2, was confirmed to be amidated by chemical synthesis, bioassay, and comparison of retention times between native and synthetic peptides. A highly specific antise rum was used to determine sites of synthesis in the abdominal ganglia. Besides periviscerokinin-1, periviscerokinin-2 is the only putative m yotropic neurohormone from the abdominal perisympathetic organs that i s effective in the nanomolar range. This confirms the hypothesis that the neurohormonal system of the ventral nerve cord is remarkably diffe rent from that of the brain. (C) 1998 Elsevier Science Inc.