Submitted to: Annals of the New York Academy of Sciences
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/9/1996
Publication Date: N/A
Citation: N/A Interpretive Summary: Because of problems with the development of resistance to conventional pesticides, there is a critical need for new concepts and alternative approaches in controlling such pests. The basic premise of this research is that peptides (short chains of amino acids) serve as internal messengers in insects to regulate vital functions. Peptides themselves are unsuitable for control measures due to their instability to insect digestive enzymes and environmental factors. New, selective control measures may be developed by designing and/or discovering chemicals that actively inhibit or stimulate peptide regulated functions, resulting in disruption of the internal environment of the insect. We have discovered that insect neuropeptides of the myosuppressin family induce release of a digestive enzyme in two invertebrates, a scallop and an insect, at low concentrations. In the future, it may be possible to develop nonpeptide mimics of this neuropeptide that are capable of disrupting the digestive processes of target insects. This work leads us one step closer to the development of practical neuropeptide-like chemicals that will be effective in controlling pest insects in an environmentally friendly manner.
Technical Abstract: Members of the insect myosuppressin and sulfakinin neuropeptide family stimulate release of the digestive enzyme alpha-amylase from cell suspensions of the stomach-digestive gland complex of the scallop Pecten maximus and isolated, ligated midgut preparations of the insect Rynchophorus ferrugineus. Leucomysosuppressin, isolated from the cockroach Leucophaea maderae, elicits over a 2-fold increase of alpha- amylase over control groups in both invertebrate assay systems. In the scallop assay, LMS demonstrates potent alpha- amylase secretagogue effects with an EC50 of 0.2 nM. The potent activity of the myosuppressins and sulfakinins suggest that these peptides may regulate release of digestive enzymes in invertebrates.