title: Effect of nitrofen in the final stages of development of the diaphragm muscle in rats.
abstract: OBJECTIVE
  To evaluate the expression of myosin in muscle fibers of the diaphragm in experimental congenital diaphragmatic hernia (CDH).
  
  
  METHODS
  Fetuses of pregnant rats were divided into four groups: External Control (EC), composed of non-manipulated rats; Nitrofen, composed of pregnant rats that received 100 mg of nitrofen (2,4-dichloro-4'nitrodiphenyl ether) diluted in olive oil on gestational day (GD) 9.5, whose fetuses developed CDH (N+) or not (N-), and Olive Oil Placebo (OO), composed of pregnant rats that received the oil on the same GD. The fetuses were collected on GD 18.5, 19.5, 20.5 and 21.5 (term = 22 days). We obtained body weight (BW) and photographed the diaphragm area (DA), hernia area (HA) and subsequent calculated the HA/DA ratio in N+ group. Samples of Diaphragm muscle were processed for histological staining with H/E and immunohistochemistry (IHQ) for myosin.
  
  
  RESULTS
  The fetuses of N- and N+ groups had decreased BW and DA compared to EC and OO groups (p < 0.001). HA was decreased on GD 18.5 compared to 21.5 (p < 0.001) and the HA/DA ratio showed no difference. IHQ showed decreased expression of myosin in nitrofen groups.
  
  
  CONCLUSIONS
  CDH induced by nitrofen model contributes to the understanding of muscularization in the formation of the diaphragm where the myosin expression is decreased.
authors: Division of Pediatric Surgery, Department of Surgery and Anatomy, School of Medicine of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, SP, Brazil.
authors: Frances Lilian Lanhellas
authors: FL
authors: Gonçalves
authors: Fábio Santana de
authors: FS
authors: Oliveira
authors: Augusto Frederico
authors: AF
authors: Schmidt
authors: Luís Antônio Violin Dias
authors: LA
authors: Pereira
authors: Rodrigo Melo
authors: RM
authors: Gallindo
authors: Rebeca Lopes
authors: RL
authors: Figueira
authors: Lourenço
authors: L
authors: Sbragia
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005260:Female; D006548:Hernia, Diaphragmatic / Q000139:chemically induced / Q000196:embryology / Q000473:pathology; D065630:Hernias, Diaphragmatic, Congenital; D007150:Immunohistochemistry; D009218:Myosins / Q000378:metabolism*; D010575:Pesticides / Q000633:toxicity*; D010647:Phenyl Ethers / Q000633:toxicity*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D010575:Pesticides; D010647:Phenyl Ethers; D009218:Myosins; C007350:nitrofen