Endogenous insect peptides

The seeds and vegetative part of plants contain several sorts of inhibitors of insect, fungal, mammalian, and endogenous proteinases. These inhibitors may be involved in plant defense mechanisms against predators and participate in the development of the plant itself. Peptidic proteinase inhibitors are well studied in the families Fabaceae, Poaceae, Asteraceae, and Solanaceae (37). Non-proteinaceous inhibitors of serine... 

In crustaceans, the kinins were isolated first on the basis of a heterologous bioassay, namely to stimulate the contraction of the hindgut of the Madeira cockroach but the crustacean kinins were also active in another insect assay, i.e. they stimulated fluid secretion in the Malpighian tubules of A. domesticus [177], Later, the 6 kinins from the prawn (Table 5) were tested in another heterologous bioassay, but at least it was on crustacean tissues all prawn kinins were able to stimulate the basal tonus of the isolated oviduct of A. leptodactylus and also enhanced the frequency and amplitude of the spontaneous contractions of the isolated hindgut of this crayfish [184], (Nonspecific assays on the hindgut of the prawn were only successful when the endogenous peptide Penva-K-1 was used at a concentration of 10"6 M [178]. 

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