title: Interstitial cells of Cajal in patients with chagasic megacolon originating from a region of old endemicity.
abstract: Megacolon is the second most frequent and most important digestive manifestation of Chagas' disease. It is characterized by motor disorders and dilatation of the distal segments of the colon. Several theories have been presented to explain the physiopathology of chagasic megacolon, e.g. the plexus theory.
  
  
  OBJECTIVE
  In the present study the distribution of interstitial cells of Cajal (ICC) was evaluated in colon biopsies from chronic chagasic patients originating from a region of old endemicity for Trypanosoma cruzi and for comparison in subjects with other colon disorders. The chagasic patients had been submitted to colectomy for the investigation of other possible mechanisms underlying the physiopathogenesis of megacolons.
  
  
  METHODS
  Twenty-two colon biopsies (15 from chagasic patients and 7 from nonchagasic patients) were examined. ICC were identified by immunohistochemistry by using the anti-CD117 antibody. The number of ICC was determined in longitudinal and circular muscle layers and in the myenteric plexus, and the results were analyzed by the Kruskal-Wallis and Student t-tests.
  
  
  RESULTS
  A reduced number of ICC was observed in all layers and in the myenteric plexus of patients with chagasic megacolon (P<0.05).
  
  
  CONCLUSIONS
  We conclude that the physiopathological manifestations observed in the large bowel of chagasic patients originate from alterations that occur in the ICC, which play an important role in the control of gut motility.
authors.affiliation: Discipline of Parasitology, Department of Biological Sciences, Faculty of Medicine of Triângulo Mineiro, Rua Frei Paulino, 30 - B. Abadia, CEP, 38025-180 Uberaba, MG, Brazil.
authors.forename: R S
authors.initials: RS
authors.lastname: Geraldino
authors.forename: A J
authors.initials: AJ
authors.lastname: Ferreira
authors.forename: M A
authors.initials: MA
authors.lastname: Lima
authors.forename: M
authors.initials: M
authors.lastname: Cabrine-Santos
authors.forename: E
authors.initials: E
authors.lastname: Lages-Silva
authors.forename: L E
authors.initials: LE
authors.lastname: Ramirez