title: An imbalance between substance P and vasoactive intestinal polypeptide might contribute to the immunopathology of megaesophagus after Trypanosoma cruzi infection.
abstract: Megaesophagus is one of the major causes of morbidity in chronic Chagas disease, and extensive denervation, associated with an inflammatory process, is recognized as the key factor for alterations in motility and disease development. Here, we analyzed esophagus samples from necropsied, infected individuals--6 cases with megaesophagus and 6 cases without megaesophagus--for the relative areas of expression of 2 neuromediators, substance P and vasoactive intestinal peptide, which are known to activate or inhibit, respectively, local immune cells. Samples from 6 noninfected individuals were used as controls. Esophageal sections were immunohistochemically stained for protein gene product 9.5, vasoactive intestinal peptide, and substance P, and the relative areas of expression of the latter 2 were calculated. Morphometric analyses revealed increased substance P and decreased vasoactive intestinal peptide relative areas in esophageal sections from patients with megaesophagus. Furthermore, in the group of patients without megaesophagus, the loss of vasoactive intestinal peptide positively correlated with the denervation process. We suggest that an imbalance between vasoactive intestinal peptide and substance P production results in the reestablishment and maintenance of the inflammatory process, leading to denervation and, consequently, promoting the development of megaesophagus.
authors.affiliation: Department of Morphology, ICB, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais 31.270-901, Brazil.
authors.forename: Rodolfo Duarte
authors.initials: RD
authors.lastname: Nascimento
authors.forename: Patrícia Rocha
authors.initials: PR
authors.lastname: Martins
authors.forename: André
authors.initials: A
authors.lastname: de Souza Lisboa
authors.forename: Sheila Jorge
authors.initials: SJ
authors.lastname: Adad
authors.forename: Alexandre Barcelos
authors.initials: AB
authors.lastname: Morais da Silveira
authors.forename: Débora d'Ávila
authors.initials: Dd
authors.lastname: Reis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014355:Chagas Disease / Q000150:complications* / Q000473:pathology; D004931:Esophageal Achalasia / Q000209:etiology / Q000378:metabolism*; D004947:Esophagus / Q000294:innervation / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009197:Myenteric Plexus / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D013373:Substance P / Q000378:metabolism*; D014349:Trypanosoma cruzi / Q000502:physiology*; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism*
chemical_list: D013373:Substance P; D014660:Vasoactive Intestinal Peptide