title: A nonpeptide provides insight into mechanisms that regulate Drosophila melanogaster heart contractions.
abstract: Here we report the effect of a nonpeptide, benzethonium chloride (bztc), on Drosophila melanogaster larval, pupal, and adult heart rates in vivo. Benzethonium chloride reduced the frequency of spontaneous contractions in the D. melanogaster pupal heart, but not in the larval heart or the adult heart as measured in noninvasive whole animal preparations. When applied directly to the D. melanogaster heart, in the absence of hemolymph, bztc reduced the frequency of spontaneous contractions in larval, pupal, and adult hearts. These findings are consistent with the conclusion that bztc acts through or is regulated by different mechanisms in these three developmental stages. An alternative explanation is that larval hemolymph and adult hemolymph contain a material that interferes with the effect of the nonpeptide on heart contractions. Bztc mimicked the effect of the peptide dromyosuppressin (DMS) on the heart at an equivalent concentration; in contrast, 103-fold more nonpeptide is required to mimic the effect of DMS on fly gut. These findings are consistent with the presence of tissue-specific myosuppressin receptors or mechanisms.
authors.affiliation: Undergraduate Cell and Molecular Biology Program, Biological Chemistry Department, University of Michigan Medical School, 4444 Medical Sciences Building I, Ann Arbor, MI 48109-0606, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Mispelon
authors.forename: Kiran
authors.initials: K
authors.lastname: Thakur
authors.forename: Leslie
authors.initials: L
authors.lastname: Chinn
authors.forename: Ryan
authors.initials: R
authors.lastname: Owen
authors.forename: Ruthann
authors.initials: R
authors.lastname: Nichols
mesh_terms: D000375:Aging / Q000502:physiology; D000818:Animals; D001558:Benzethonium / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004331:Drosophila melanogaster / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D007267:Injections; D007814:Larva / Q000187:drug effects / Q000502:physiology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D011679:Pupa / Q000187:drug effects / Q000502:physiology
chemical_list: D001558:Benzethonium