title: Distribution of the P2X2 receptor and chemical coding in ileal enteric neurons of obese male mice (ob/ob).
abstract: OBJECTIVE
  To investigate the colocalization, density and profile of neuronal areas of enteric neurons in the ileum of male obese mice.
  
  
  METHODS
  The small intestinal samples of male mice in an obese group (OG) (C57BL/6J ob/ob) and a control group (CG) (+/+) were used. The tissues were analyzed using a double immunostaining technique for immunoreactivity (ir) of the P2X2 receptor, nitric oxide synthase (NOS), choline acetyl transferase (ChAT) and calretinin (Calr). Also, we investigated the density and profile of neuronal areas of the NOS-, ChAT- and Calr-ir neurons in the myenteric plexus. Myenteric neurons were labeled using an NADH-diaphorase histochemical staining method.
  
  
  RESULTS
  The analysis demonstrated that the P2X2 receptor was expressed in the cytoplasm and in the nuclear and cytoplasmic membranes only in the CG. Neuronal density values (neuron/cm(2)) decreased 31% (CG: 6579 ± 837; OG: 4556 ± 407) and 16.5% (CG: 7796 ± 528; OG: 6513 ± 610) in the NOS-ir and calretinin-ir neurons in the OG, respectively (P < 0.05). Density of ChAT-ir (CG: 6200 ± 310; OG: 8125 ± 749) neurons significantly increased 31% in the OG (P < 0.05). Neuron size studies demonstrated that NOS, ChAT, and Calr-ir neurons did not differ significantly between the CG and OG groups. The examination of NADH-diaphorase-positive myenteric neurons revealed an overall similarity between the OG and CG.
  
  
  CONCLUSIONS
  Obesity may exert its effects by promoting a decrease in P2X2 receptor expression and modifications in the density of the NOS-ir, ChAT-ir and CalR-ir myenteric neurons.
authors.affiliation: Márcia Sanae Mizuno, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: Márcia Sanae
authors.initials: MS
authors.lastname: Mizuno
authors.affiliation: Márcia Sanae Mizuno, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: Amanda Rabello
authors.initials: AR
authors.lastname: Crisma
authors.affiliation: Márcia Sanae Mizuno, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: Primavera
authors.initials: P
authors.lastname: Borelli
authors.affiliation: Márcia Sanae Mizuno, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: Bárbara Tavares
authors.initials: BT
authors.lastname: Schäfer
authors.affiliation: Márcia Sanae Mizuno, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: Mariana Póvoa
authors.initials: MP
authors.lastname: Silveira
authors.affiliation: Márcia Sanae Mizuno, Patricia Castelucci, Department of Anatomy/Biomedical Science Institute, University of São Paulo, São Paulo 05508-900, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Castelucci
mesh_terms: D000818:Animals; D064032:Calbindin 2 / Q000032:analysis; D002795:Choline O-Acetyltransferase / Q000032:analysis; D004195:Disease Models, Animal; D015536:Down-Regulation; D017615:Enteric Nervous System / Q000737:chemistry* / Q000503:physiopathology; D007082:Ileum / Q000294:innervation*; D007150:Immunohistochemistry; D008297:Male; D008810:Mice, Inbred C57BL; D008820:Mice, Obese; D019001:Nitric Oxide Synthase / Q000032:analysis; D009765:Obesity / Q000378:metabolism* / Q000503:physiopathology; D058476:Receptors, Purinergic P2X2 / Q000032:analysis*
chemical_list: C576511:Calb2 protein, mouse; D064032:Calbindin 2; C546402:P2rx2 protein, mouse; D058476:Receptors, Purinergic P2X2; D019001:Nitric Oxide Synthase; D002795:Choline O-Acetyltransferase
keywords: Chemical coding; Myenteric neurons; Obesity; P2X2 receptor