title: Tachykinin neuropeptide-evoked intracellular calcium transients in cultured guinea pig myenteric neurons.
abstract: Substance P and related tachykinins are present in the mammalian gut and act as neurotransmitters. Microfluorimetric measurement of intracellular calcium ([Ca2+]i) was used to study tachykinin-sensitive myenteric neurons. Substance P (0.001-10 microM) evoked concentration-dependent increases in percentage of neurons responding (6-75%) and delta [Ca2+]i (88 +/- 24 to 212 +/- 16 nM). Neurokinin A (0.001-1 microM) produced similar responses. Removal of extracellular Ca2+ abolished substance P-induced Ca2+ signals, as did the addition of the Ca2+ channel blockers lanthanum chloride (5 mM) and nickel chloride (2.5 mM). Both nifedipine (1-50 microM) and diltiazem (1-50 microM) inhibited substance P-evoked Ca2+ responses in a dose-dependent manner. Substance P and related tachykinins evoke Ca2+ signaling in cultured myenteric neurons by the influx of extracellular Ca2+ through L and N-type plasma membrane Ca2+ channels.
authors.affiliation: Department of Surgery, University of Michigan, Ann Arbor 48109-0331, USA.
authors.forename: G A
authors.initials: GA
authors.lastname: Sarosi
authors.forename: B C
authors.initials: BC
authors.lastname: Kimball
authors.forename: D C
authors.initials: DC
authors.lastname: Barnhart
authors.forename: W
authors.initials: W
authors.lastname: Zhang
authors.forename: M W
authors.initials: MW
authors.lastname: Mulholland
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000378:metabolism; D002478:Cells, Cultured; D004110:Diltiazem / Q000494:pharmacology; D004151:Dipeptides / Q000494:pharmacology; D005470:Fluorometry; D006168:Guinea Pigs; D007211:Indoles / Q000494:pharmacology; D007811:Lanthanum / Q000494:pharmacology; D009197:Myenteric Plexus / Q000187:drug effects* / Q000378:metabolism; D015288:Neurokinin A / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology; D009543:Nifedipine / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D018039:Receptors, Tachykinin / Q000819:agonists / Q000145:classification; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology*; D015320:Tachykinins / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004151:Dipeptides; D007211:Indoles; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D018039:Receptors, Tachykinin; D015320:Tachykinins; D010566:Virulence Factors, Bordetella; C054724:senktide; C073361:cyclo(Gln-Trp-Phe-Gly-Leu-Met); C078949:FK 888; D013373:Substance P; D007811:Lanthanum; D009532:Nickel; D015288:Neurokinin A; D004110:Diltiazem; D009543:Nifedipine; D002118:Calcium