title: The detection of AKH/HrTH-like peptides in Ascaridia galli and Ascaris suum using an insect hyperglycaemic bioassay.
abstract: Evidence for the presence of adipokinetic hormone/hypertrehalosaemic hormone (AKH/HrTH)-like peptides in the parasitic nematodes Ascaridia galli and Ascaris suum has been obtained using insect bioassays which measure hyperglycaemic responses to peptides belonging to the AKH/HrTH family of insect hormones. A peptide fraction extracted from heads and tails of Ascaridia galli evoked a dose-dependent hyperglycaemic response when injected into the cockroach, Periplaneta americana. Maximal bioactivity was obtained with material that was equivalent to 38 mg (wet weight) of nematode. Bioactivity appeared to be highest in extracts from heads and tails of both male and female worms and could be fractionated into at least three peaks of hyperglycaemic activity by reversed-phase high-performance liquid chromatography. An extract from heads and tails of A. suum also evoked a hyperglycaemic response when injected into the cockroach, Blaberus discoidalis. The bioactivity was inactivated on incubation with pure endopeptidase 24.11, confirming the peptidic nature of the bioactive material. These results provide evidence for the existence of peptides related to the insect AKH/HrTH family of peptides in parasitic nematodes.
authors.affiliation: Department of Pure and Applied Biology, University of Leeds, UK.
authors.forename: T R
authors.initials: TR
authors.lastname: Davenport
authors.forename: L A
authors.initials: LA
authors.lastname: Eaves
authors.forename: T K
authors.initials: TK
authors.lastname: Hayes
authors.forename: D L
authors.initials: DL
authors.lastname: Lee
authors.forename: R E
authors.initials: RE
authors.lastname: Isaac
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001197:Ascaridia / Q000737:chemistry*; D017165:Ascaris suum / Q000737:chemistry*; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D005260:Female; D015801:Helminth Proteins / Q000032:analysis* / Q000737:chemistry; D007301:Insect Hormones / Q000032:analysis* / Q000737:chemistry; D008297:Male; D008969:Molecular Sequence Data; D009479:Neuropeptides / Q000032:analysis* / Q000737:chemistry; D009842:Oligopeptides / Q000032:analysis* / Q000737:chemistry; D010526:Periplaneta; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives
chemical_list: D015801:Helminth Proteins; D007301:Insect Hormones; D009479:Neuropeptides; D009842:Oligopeptides; C044833:adipokinetic hormone; C068004:hypertrehalosemic neuropeptide; D011761:Pyrrolidonecarboxylic Acid