title: Role of Phote-HrTH (Phormia terraenovae hypertrehalosemic hormone) in modulating the supercontractile muscles of the crop of adult Phormia regina Meigen.
abstract: Phote-HrTH (Phormia terraenovae hypertrehalosemic hormone) has been demonstrated in the Diptera to be involved in flight metabolism, reproduction, and diapause. Each of these events needs the hormone's action and requirement for carbohydrates is the common denominator. In Diptera, carbohydrates are taken up during feeding by action of the cibarial pump and are then stored in the crop. Using adult Phormia regina, both a bioassay and electrophysiological recordings show that Phote-HrTH slows down or inhibits the crop lobe muscles (P5) and, at the same time, stimulates the muscles of the pump 4 (P4) involved in pushing fluids out of the crop and up into the midgut for digestion. The EC50 for P4 was in the nanomolar range while the IC50 for P5 was 1.4-75.1 pM. The effect of Phote-HrTH on P4/5 suggests that the peptide is important in coordinating the two pumps, which are involved in moving carbohydrates up into the midgut for digestion. The adult crop organ is an essential storage organ for carbohydrates and now should be considered an important structure capable of delivering nutrients to the midgut for digestion.
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA. Electronic address: stoff@umass.edu.
authors.forename: John G
authors.initials: JG
authors.lastname: Stoffolano
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Croke
authors.affiliation: Department of Chemistry, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: James
authors.initials: J
authors.lastname: Chambers
authors.affiliation: Department of Biological Sciences, University of Cape Town, ZA-7701 Rondebosch, South Africa.
authors.forename: Gerd
authors.initials: G
authors.lastname: Gäde
authors.affiliation: Department of Biomedical Sciences, University of Cagliari, University Campus, S.P. 8, I-09042 Monserrato (CA), Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Solari
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, University Campus, S.P. 8, I-09042 Monserrato (CA), Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Liscia
mesh_terms: D000818:Animals; D004175:Diptera / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D007301:Insect Hormones / Q000378:metabolism*; D019476:Insect Proteins / Q000378:metabolism*; D009119:Muscle Contraction; D054792:Muscle, Striated / Q000502:physiology; D009479:Neuropeptides / Q000378:metabolism*
chemical_list: D007301:Insect Hormones; D019476:Insect Proteins; D009479:Neuropeptides; C084112:hypertrehalosemic hormone
keywords: AKH; Dipteran crop; Neuropeptide; Supercontractile muscles