title: Senktide-induced gerbil foot tapping behaviour is blocked by selective tachykinin NK1 and NK3 receptor antagonists.
abstract: Intracerebroventricular (i.c.v.) administration of tachykinin NK(1) receptor agonists induces tapping of the hind legs in gerbils, so-called gerbil foot tapping, which is thought to reflect a fear-related response. The aim of the present study was to examine how ligands selective for NK(1), NK(2) and NK(3) receptors affect the gerbil foot tap response. Agonists selective for NK receptor subtypes were administered i.c.v. and the gerbil foot tap response was monitored. The effect of systemically administered antagonists was also studied. The interaction of ligands with gerbil NK(1) receptors was evaluated using autoradiography on gerbil brain slices with [(3)H]-Sar,Met(O(2))-substance P or [(3)H]GR205171 as radioligand. The effects of ligands on NK(1) and NK(3) receptor-mediated increases in intracellular calcium in vitro were studied in Chinese hamster ovary cells expressing the cloned gerbil receptors. The selective NK(1) receptor agonist ASMSP and the selective NK(3) receptor agonist senktide induced dose-dependent increases in gerbil foot tapping with similar potency. The maximal effect of senktide was approximately 40% of the maximal response evoked by ASMSP. The effects of ASMSP and senktide were blocked by administration of the selective NK(1) receptor antagonist CP99,994 (10 micromol/kg s.c.). The effects of senktide, but not ASMSP, were blocked by administration of the selective NK(3) receptor antagonist SB223412 (50 micromol/kg i.p.). Senktide did not displace NK(1) receptor radioligand binding and was >1000-fold less potent than ASMSP at activating gerbil NK(1) receptors. The selective NK(3) receptor agonist senktide evokes fear-related gerbil foot tapping, an effect which probably involves indirect enhancement of NK(1) receptor signalling.
authors.affiliation: AstraZeneca R&D, Mölndal, Sweden.
authors.forename: Monika
authors.initials: M
authors.lastname: Sundqvist
authors.forename: Elin
authors.initials: E
authors.lastname: Kristensson
authors.forename: Rebecka
authors.initials: R
authors.lastname: Adolfsson
authors.forename: Agnes
authors.initials: A
authors.lastname: Leffler
authors.forename: Ingela
authors.initials: I
authors.lastname: Ahlstedt
authors.forename: Susanna
authors.initials: S
authors.lastname: Engberg
authors.forename: Tomas
authors.initials: T
authors.lastname: Drmota
authors.forename: Kalle
authors.initials: K
authors.lastname: Sigfridsson
authors.forename: Rainer
authors.initials: R
authors.lastname: Jussila
authors.forename: Jennie
authors.initials: J
authors.lastname: de Verdier
authors.forename: Anna
authors.initials: A
authors.lastname: Novén
authors.forename: Anders
authors.initials: A
authors.lastname: Johansson
authors.forename: Ingrid
authors.initials: I
authors.lastname: Påhlman
authors.forename: Bengt
authors.initials: B
authors.lastname: von Mentzer
authors.forename: Erik
authors.initials: E
authors.lastname: Lindström
mesh_terms: D000818:Animals; D001345:Autoradiography; D001522:Behavior, Animal / Q000187:drug effects*; D001921:Brain / Q000378:metabolism; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism; D003001:Cloning, Molecular; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D005528:Foot; D005849:Gerbillinae; D007276:Injections, Intraventricular; D008297:Male; D015288:Neurokinin A / Q000031:analogs & derivatives / Q000494:pharmacology; D064729:Neurokinin-1 Receptor Antagonists; D010446:Peptide Fragments / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D010880:Piperidines / Q000494:pharmacology; D011804:Quinolines / Q000494:pharmacology; D018041:Receptors, Neurokinin-2 / Q000037:antagonists & inhibitors; D018042:Receptors, Neurokinin-3 / Q000037:antagonists & inhibitors*; D013373:Substance P / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: D064729:Neurokinin-1 Receptor Antagonists; D010446:Peptide Fragments; D010880:Piperidines; D011804:Quinolines; D018041:Receptors, Neurokinin-2; D018042:Receptors, Neurokinin-3; C082580:substance P(4-11), beta Ala(4)-Ser(9)-Met(O2)(11)-; C054724:senktide; C068032:GR 73632; C068031:neurokinin A (3-10), lysyl(3)-glycyl(8)-R-lactam-leucine(9)-; C080755:3-(2-methoxybenzylamino)-2-phenylpiperidine; C106716:SB 223412; D013373:Substance P; D015288:Neurokinin A; D002118:Calcium