title: Postnatal development of the dopaminergic signaling involved in the modulation of intestinal motility in mice.
abstract: Since antidopaminergic drugs are pharmacological agents employed in the management of gastrointestinal motor disorders at all ages, we investigated whether the enteric dopaminergic system may undergo developmental changes after birth.
  
  
  
  Intestinal mechanical activity was examined in vitro as changes in isometric tension.
  
  
  
  In 2-d-old (P2) mice, dopamine induced a contractile effect, decreasing in intensity with age, replaced, at the weaning (day 20), by a relaxant response. Both responses were tetrodotoxin (TTX)-insensitive. In P2, dopaminergic contraction was inhibited by D1-like receptor antagonist and mimicked by D1-like receptor agonist. In 90-d-old (P90) mice, the relaxation was reduced by both D1- and D2-like receptor antagonists, and mimicked by D1- and D2-like receptor agonists. In P2, contraction was antagonized by phospholipase C inhibitor, while in P90 relaxation was antagonized by adenylyl cyclase inhibitor and potentiated by phospholipase C inhibitor. The presence of dopamine receptors was assessed by immunofluorescence. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed a significant increase in D1, D2, and D3 receptor expression in proximal intestine with the age.
  
  
  
  In mouse small intestine, the response to dopamine undergoes developmental changes shifting from contraction to relaxation at weaning, as the consequence of D2-like receptor recruitment and increased expression of D1 receptors.
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Palermo, Università di Palermo, Palermo, Italia.
authors.forename: Maria Grazia
authors.identifier: 0000-0003-1996-6529
authors.initials: MG
authors.lastname: Zizzo
authors.affiliation: NICU, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milano, Italia.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Cavallaro
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Palermo, Università di Palermo, Palermo, Italia.
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Auteri
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Palermo, Università di Palermo, Palermo, Italia.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Caldara
authors.affiliation: NICU, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milano, Italia.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Amodeo
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Palermo, Università di Palermo, Palermo, Italia.
authors.forename: Mariangela
authors.initials: M
authors.lastname: Mastropaolo
authors.affiliation: Istituto di Biomedicina ed Immunologia Molecolare (IBIM) "Alberto Monroy," CNR, Palermo, Italia.
authors.forename: Domenico
authors.initials: D
authors.lastname: Nuzzo
authors.affiliation: Istituto di Biomedicina ed Immunologia Molecolare (IBIM) "Alberto Monroy," CNR, Palermo, Italia.
authors.forename: Marta
authors.initials: M
authors.lastname: Di Carlo
authors.affiliation: NICU, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milano, Italia.
authors.forename: Monica
authors.initials: M
authors.lastname: Fumagalli
authors.affiliation: NICU, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Università degli Studi di Milano, Milano, Italia.
authors.forename: Fabio
authors.initials: F
authors.lastname: Mosca
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Palermo, Università di Palermo, Palermo, Italia.
authors.forename: Flavia
authors.initials: F
authors.lastname: Mule
authors.affiliation: Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche (STEBICEF), Laboratorio di Fisiologia generale, Palermo, Università di Palermo, Palermo, Italia.
authors.forename: Rosa
authors.initials: R
authors.lastname: Serio
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D000242:Cyclic AMP / Q000378:metabolism; D016048:Dideoxyadenosine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D017615:Enteric Nervous System / Q000502:physiology; D004963:Estrenes / Q000494:pharmacology; D005767:Gastrointestinal Diseases / Q000473:pathology; D005769:Gastrointestinal Motility / Q000502:physiology*; D007421:Intestine, Small / Q000254:growth & development* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D011760:Pyrrolidinones / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D013779:Tetrodotoxin / Q000737:chemistry; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D004963:Estrenes; D011760:Pyrrolidinones; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D013779:Tetrodotoxin; D016048:Dideoxyadenosine; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000242:Cyclic AMP; D010738:Type C Phospholipases; D004298:Dopamine