title: Plasticity in the effects of sulfated and nonsulfated sulfakinin on heart contractions.
abstract: Neuropeptides regulate the frequency of heart contractions. Drosophila melanogaster sulfakinin (drosulfakinin) encodes FDDYGHMRFamide, DSK I, and GGDDQFDDYGHMRFamide, DSK II. Invertebrate sulfakinins are structurally and functionally related to vertebrate cholecystokinins. Naturally-occurring drosulfakinins contain a sulfated or nonsulfated tyrosine and are designated sDSK I, sDSK II, nsDSK I, and nsDSK II. We developed a novel neural-cardiovascular preparation and investigated mechanisms regulating the effect of sulfakinins on D. melanogaster heart. We established the preparation in larva, pupa, and adult to examine plasticity in neural regulation of cardiovascular parameters. We discovered sDSK I increased the frequency of larval, pupal, and adult heart contractions; nsDSK I only increased the frequency of larval contractions, not pupal or adult. We also discovered sDSK II and nsDSK II increased the frequency of larval and adult contractions, not pupal. This is the first report of nonsulfated sulfakinin activity on heart, and sulfakinin activity examined in 3 developmental stages within the same animal species. Our data demonstrate a role for plasticity in the effects of sulfakinins on heart contractions, and suggest multiple mechanisms are involved.
authors.affiliation: Biological Chemistry Department, University of Michigan Medical School, Medical Science Research Building III, Ann Arbor, MI, 48109-0606, USA. nicholsr@umich.edu
authors.forename: Ruthann
authors.initials: R
authors.lastname: Nichols
authors.forename: Beth
authors.initials: B
authors.lastname: Manoogian
authors.forename: Emilie
authors.initials: E
authors.lastname: Walling
authors.forename: Melissa
authors.initials: M
authors.lastname: Mispelon
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster; D036341:Intercellular Signaling Peptides and Proteins; D009200:Myocardial Contraction / Q000187:drug effects*; D009479:Neuropeptides / Q000737:chemistry / Q000494:pharmacology*; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D036341:Intercellular Signaling Peptides and Proteins; D009479:Neuropeptides; D009842:Oligopeptides; D010455:Peptides; C056936:drosulfakinin 1; C056938:drosulfakinin II