title: Diuretic action of the peptide locustatachykinin I: cellular localisation and effects on fluid secretion in Malpighian tubules of locusts.
abstract: In insects primary urine is produced by the Malpighian tubules under hormonal control. Here we have analysed the effects of the peptide locustatachykinin I (Lom-TK-I) on secretion in isolated Malphigian tubules. We also mapped the distribution of Lom-TK immunoreactivity in the gut in comparison with Locusta diuretic hormone (Lom-DH) and serotonin, two other factors that are active on locust tubules. Lom-TK-I produces an immediate, potent and long-lasting stimulation of fluid secretion. Furthermore, we show that Lom-TK-I acts synergistically with Lom-DH on fluid secretion and demonstrate that Lom-TKs are co-localised with Lom-DH in endocrine cells of the midgut ampullae. Thus, the two peptides might be released together to act synergistically on fluid secretion. Also serotonin and Lom-DH act synergistically and we can demonstrate a plexus of serotonin-containing axon processes over the midgut.
authors.affiliation: Department of Zoology, Stockholm University, Svante Arrhenius väg 14, SE-106 91, Stockholm, Sweden.
authors.forename: Helena A D
authors.initials: HA
authors.lastname: Johard
authors.forename: Geoff M
authors.initials: GM
authors.lastname: Coast
authors.forename: William
authors.initials: W
authors.lastname: Mordue
authors.forename: Dick R
authors.initials: DR
authors.lastname: Nässel
mesh_terms: D000818:Animals; D001369:Axons / Q000276:immunology; D001826:Body Fluids / Q000378:metabolism*; D004232:Diuretics / Q000032:analysis* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006110:Grasshoppers / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D007150:Immunohistochemistry; D007301:Insect Hormones / Q000032:analysis / Q000494:pharmacology; D019476:Insect Proteins / Q000032:analysis* / Q000494:pharmacology*; D008297:Male; D008317:Malpighian Tubules / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D012701:Serotonin / Q000276:immunology; D015320:Tachykinins / Q000032:analysis* / Q000494:pharmacology*
chemical_list: D004232:Diuretics; D007301:Insect Hormones; D019476:Insect Proteins; D015320:Tachykinins; C063413:locustatachykinin I protein, Locusta migratoria; D012701:Serotonin