title: Distribution of heme oxygenase-2 in nerves and interstitial cells of Cajal in the normal pylorus and in infantile hypertrophic pyloric stenosis.
abstract: BACKGROUND
  Interstitial cells of Cajal (ICCs) are pacemaker cells, which are of fundamental importance in regulating gastrointestinal motility. Recent evidence suggests that carbon monoxide is a neurotransmitter involved in neurotransmission between ICC and smooth muscle cells. Heme oxygenase-2 (HO-2) is the major physiological mechanism for the generation of carbon monoxide in the enteric nervous system.
  
  
  OBJECTIVE
  To investigate the immunocolocalization of HO-2 and ICCs in the normal pylorus and in infantile hypertrophic pyloric stenosis (IHPS).
  
  
  METHODS
  Specimens from 18 infants with IHPS and 8 control specimens were examined using double-immunostaining with c-Kit and HO-2 antibodies. The immunolocalization was detected with the help of confocal laser scanning microscopy.
  
  
  RESULTS
  Abundant HO-2 immunoreactivity was found in ICCs in the smooth muscle layer of normal pylorus. There was a decrease in the number of ICCs and lack of HO-2 immunoreactivity in ICCs in IHPS.
  
  
  CONCLUSIONS
  The results of the present study provide the first evidence for the presence of HO-2 in ICCs in the normal human pylorus. The lack of ICCs and HO-2 in IHPS suggests impaired intracellular communication between ICCs and smooth muscle cells, contributing to motility dysfunction in IHPS.
authors.affiliation: Children's Research Centre, Our Lady's Hospital for Sick Children and University College Dublin, Dublin, Ireland.
authors.forename: Anna Piaseczna
authors.initials: AP
authors.lastname: Piotrowska
authors.forename: Valeria
authors.initials: V
authors.lastname: Solari
authors.forename: Prem
authors.initials: P
authors.lastname: Puri
mesh_terms: D017615:Enteric Nervous System / Q000201:enzymology*; D005260:Female; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D006801:Humans; D006984:Hypertrophy; D007150:Immunohistochemistry; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D018613:Microscopy, Confocal; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis; D011707:Pyloric Stenosis / Q000201:enzymology* / Q000473:pathology; D011708:Pylorus / Q000166:cytology / Q000201:enzymology*
chemical_list: D006419:Heme Oxygenase (Decyclizing); C105245:heme oxygenase-2; D019009:Proto-Oncogene Proteins c-kit