title: Moderate physical exercise protects myenteric metabolically more active neurons in mice infected with Trypanosoma cruzi.
abstract: BACKGROUND
  Trypanosoma cruzi causes neuronal myenteric depopulation compromising intestinal function.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the influence of moderate physical exercise on NADH diaphorase (NADH-d)-positive neurons in the myenteric plexus and intestinal wall of the colon in mice infected with T. cruzi.
  
  
  METHODS
  Forty 30-day-old male Swiss mice were divided into the following groups: trained infected (TI), sedentary infected (SI), trained control (TC), and sedentary control. The TC and TI groups were subjected to a moderate physical exercise program on a treadmill for 8 weeks. Three days after finishing physical exercise, the TI and SI groups were intraperitoneally inoculated with 1,300 blood trypomastigotes of the Y strain of Trypanosoma cruzi. Parasitemia was evaluated from days 4 to 61 after inoculation. On day 75 of infection, myenteric neurons in the colon were quantified (NADH-d), and inflammatory foci were counted. Tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) levels were evaluated in plasma. The results were compared using analysis of variance and the Kruskal-Wallis test at a 5 % significance level.
  
  
  RESULTS
  Moderate physical exercise reduced the parasite peak on day 8 of infection (p = 0.0132) and total parasitemia (p = 0.0307). It also prevented neuronal depopulation (p < 0.01), caused hypertrophy of these cells (p < 0.05), prevented the formation of inflammatory foci (p < 0.01), and increased the synthesis of TNF-α (p < 0.01) and TGF-β (p > 0.05).
  
  
  CONCLUSIONS
  These results reinforce the therapeutic benefits of moderate physical exercise for T. cruzi infection.
authors.affiliation: Graduate Program in Health Sciences, State University of Maringa, Columbus Avenue, 5790, Zone 07, Maringá, PR, 87020-900, Brazil, neidemartinsenf@yahoo.com.br.
authors.forename: Neide Martins
authors.initials: NM
authors.lastname: Moreira
authors.forename: Solange Marta Franzói
authors.initials: SM
authors.lastname: de Moraes
authors.forename: M M O
authors.initials: MM
authors.lastname: Dalálio
authors.forename: Mônica Lúcia
authors.initials: ML
authors.lastname: Gomes
authors.forename: D M G
authors.initials: DM
authors.lastname: Sant'ana
authors.forename: Silvana Marques
authors.initials: SM
authors.lastname: de Araújo
mesh_terms: D000818:Animals; D014355:Chagas Disease / Q000097:blood / Q000469:parasitology / Q000473:pathology / Q000628:therapy*; D003106:Colon / Q000294:innervation*; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D004195:Disease Models, Animal; D006984:Hypertrophy; D018836:Inflammation Mediators / Q000097:blood; D008297:Male; D051379:Mice; D009197:Myenteric Plexus / Q000378:metabolism / Q000469:parasitology* / Q000473:pathology; D009474:Neurons / Q000378:metabolism / Q000469:parasitology* / Q000473:pathology; D005082:Physical Exertion; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000097:blood; D014349:Trypanosoma cruzi / Q000472:pathogenicity*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D018836:Inflammation Mediators; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D008058:Dihydrolipoamide Dehydrogenase