Regulation of bombykol production by tyramine and octopamine in Bombyx mori

The relationship between bombykol production and biogenic amines in brain-suboesophageal ganglion (SOG) complexes in Bombyx mori was investigated using reversed-phase high-performance liquid chromatography (HPLC) with electrochemical detection (ECD). Changes in octopamine (OA), dopamine (DA) and tyramine (TA) levels in brain-SOG complexes relative to mating stimuli were examined. TA increased significantly after mating, whereas there were no significant differences in OA and DA levels in brain-SOG complexes between virgin and mated females. Receptors can either inhibit or activate adenylate-cyclase activity by TA or OA in the central nervous system. Involvement of TA and OA in insect sex-pheromone production is discussed. The present studies could provide useful information for the characterization and differentiation of TA and OA receptors, and may help to point the way towards developing extremely potent and relatively specific TA or OA ligands, leading to potential insecticides, although further research is necessary.