title: The effects of chronically increased intra-abdominal pressure on the rabbit diaphragm.
abstract: BACKGROUND
  Diaphragmatic muscular remodeling is caused by various conditions and was mainly studied in pulmonary pathologies and chronic alterations of intra-thoracic pressure. We investigate the effect of the chronically increased intra-abdominal pressure (IAP) on the diaphragm by morphological and biochemical analysis.
  
  
  METHODS
  Thirty rabbits were divided into control and study groups. IAP was increased in group B to 12 mmHg for 2 months. The left hemidiaphragm underwent morphological, while the right underwent biochemical analysis.
  
  
  RESULTS
  In H&E, all fibers were normal. ATPase analysis demonstrated that type I fibers show no differences between groups. Type ΙΙ(Α) were decreased (p = 0.016) while type ΙΙ(Β/X) fibers were increased (p = 0.025) in group B. Fibers with resistance to fatigue were decreased in group B (p = 0.024). In group B, biochemical activity for glutathione reductase (p = 0.004), glutathione peroxidase (p = 0.021), protein carbonylation (0.029), lipid peroxidation (p = 0.005), and balance of preoxidative-antioxidative factors (p = 0.006) was increased.
  
  
  CONCLUSIONS
  Chronically increased IAP induces alterations to the rabbit diaphragm. Adaptation, equivalent to strenuous contraction, transforms the diaphragm to be functionally more efficient toward workload but makes it vulnerable against oxidative stress.
authors.affiliation: 3rd Department of Surgery, AHEPA University Hospital, Aristotle University of Thessaloniki, Aigaiou 6, 54655, Thessaloniki, Greece. Papavramidis@hotmail.com
authors.forename: Theodossis S
authors.initials: TS
authors.lastname: Papavramidis
authors.forename: Efstathios
authors.initials: E
authors.lastname: Kotidis
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Ioannidis
authors.forename: Angeliki
authors.initials: A
authors.lastname: Cheva
authors.forename: Thomai
authors.initials: T
authors.lastname: Lazou
authors.forename: George
authors.initials: G
authors.lastname: Koliakos
authors.forename: George
authors.initials: G
authors.lastname: Karkavelas
authors.forename: Spiros T
authors.initials: ST
authors.lastname: Papavramidis
mesh_terms: D000009:Abdominal Muscles / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D003964:Diaphragm / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D059325:Intra-Abdominal Hypertension / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D015227:Lipid Peroxidation; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000473:pathology; D018657:Muscle Fibers, Slow-Twitch / Q000473:pathology; D018384:Oxidative Stress; D011312:Pressure; D050050:Protein Carbonylation; D011817:Rabbits
chemical_list: D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D000251:Adenosine Triphosphatases