title: Effects of ischemia and reperfusion on subpopulations of rat enteric neurons expressing the P2X7 receptor.
abstract: BACKGROUND
  Intestinal ischemia followed by reperfusion (I/R) may occur following intestinal obstruction. In rats, I/R in the small intestine leads to structural changes accompanied by neuronal death.
  
  
  OBJECTIVE
  To analyze the impact of I/R injury on different neuronal populations in the myenteric plexus of rat ileum.
  
  
  METHODS
  The ileal artery was occluded for 35 min and animals were euthanized 6, 24, and 72 h, and 1 week later. Immunohistochemistry was performed with antibodies against the P2X7 receptor as well as nitric oxide synthase (NOS), calbindin, calretinin, choline acetyltransferase (ChAT), or the pan-neuronal marker anti-HuC/D.
  
  
  RESULTS
  Double immunolabeling demonstrated that 100% of NOS-, calbindin-, calretinin-, and ChAT-immunoreactive neurons in all groups expressed the P2X7 receptor. Following I/R, neuronal density decreased by 22.6% in P2X7 receptor-immunoreactive neurons, and decreased by 46.7, 38, 39.8, 21.7, and 20% in NOS-, calbindin-, calretinin-, ChAT-, and HuC/D-immunoreactive neurons, respectively, at 6, 24, and 72 h and 1 week following injury compared to the control and sham groups. We also observed a 14% increase in the neuronal cell body profile area of the NOS-immunoreactive neurons at 6 and 24 h post-I/R and a 14% increase in ChAT-immunoreactive neurons at 1 week following I/R. However, the average size of the calretinin-immunoreactive neurons was reduced by 12% at 6 h post-I/R and increased by 8% at 24 h post-I/R.
  
  
  CONCLUSIONS
  This work demonstrates that I/R is associated with a significant loss of different subpopulations of neurons in the myenteric plexus accompanied by morphological changes, all of which may underlie conditions related to intestinal motility disorder.
authors.affiliation: Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, Av. Prof. Dr. Lineu Prestes, 2415, São Paulo, CEP 05508-900, Brazil.
authors.forename: Kelly
authors.initials: K
authors.lastname: Palombit
authors.forename: Cristina Eusébio
authors.initials: CE
authors.lastname: Mendes
authors.forename: Wothan
authors.initials: W
authors.lastname: Tavares-de-Lima
authors.forename: Mariana Póvoa
authors.initials: MP
authors.lastname: Silveira
authors.forename: Patricia
authors.initials: P
authors.lastname: Castelucci
mesh_terms: D000818:Animals; D001699:Biometry; D015536:Down-Regulation / Q000235:genetics; D007415:Intestinal Obstruction / Q000150:complications / Q000235:genetics; D007511:Ischemia / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D008297:Male; D009197:Myenteric Plexus / Q000378:metabolism / Q000473:pathology*; D009474:Neurons / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D058486:Receptors, Purinergic P2X7 / Q000096:biosynthesis*; D015424:Reperfusion / Q000009:adverse effects; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D058486:Receptors, Purinergic P2X7