title: The effect of hyperbaric oxygen on apoptosis and proliferation in severe acute pancreatitis.
abstract: OBJECTIVE
  This paper investigates the significance of apoptosis in severe acute pancreatitis (SAP) and the possible modulating effects of hyperbaric oxygen (HBO).
  
  
  METHODS
  Wistar rats (250-350 g) were induced with SAP by biliopancreatic infusion of 4% sodium taurocholate. Rats were randomized for HBO treatment. Pancreatic tissue was stained for apoptosis with immunohistochemistry (anti-CASPASE-3 antibody and TUNEL), and histopathology haematoxylin and eosin (H&E). Acini were stained for proliferation with an anti-KI67 antibody. ImageProPlus was used to quantify apoptosis and proliferation in acinar cells. Statistical analysis was performed with two-independent-sample t-test or non-parametric Mann-Whitney test.
  
  
  RESULTS
  In normal acini there is a low rate of apoptosis (0.165 +/- 0.157%, 0.181 +/- 0.168%, 0.130 +/- 0.298% in CASPASE-3, H&E and TUNEL, respectively) and proliferation (0.951 +/- 0.926%) (mean +/- standard deviation [SD]). When compared with normal, apoptosis (CASPASE-3: 1.28 +/- 1.12%, P= 0.008; 2.40 +/- 3.04%, P= 0.101; 1.23 +/- 0.87%, P= 0.091; H&E: 0.47 +/- 0.36%, P= 0.051; 0.69 +/- 0.63%, P= 0.001; 0.68 +/- 0.28%, P= 0; TUNEL: 1.08 +/- 1.42%, P= 0; 1.96 +/- 1.87%, P= 0; 2.36 +/- 2.26%, P= 0) and proliferation (1.96 +/- 1.89%, P= 0.187; 1.73 +/- 1.76%, P= 0.165; 1.36 +/- 1.40%, P= 0.571) were increased on days 1, 2 and 3 post-induction, respectively. In comparison with the untreated controls, HBO increased apoptosis on day 1 (CASPASE-3: 3.11 +/- 1.97%, P= 0.04; H&E: 0.97 +/- 0.76%, P= 0.005) and day 2 (TUNEL: 3.61 +/- 3.05%, P= 0.034). Treatment with HBO increased proliferation (3.04 +/- 3.14%, P= 0.519; 7.33 +/- 7.55%, P= 0.153) on days 2 and 3, respectively, compared with the untreated controls.
  
  
  CONCLUSIONS
  During SAP, acini apoptosis and proliferation were increased. Hyperbaric oxygen therapy may improve the condition of SAP by promoting apoptosis and proliferation.
authors.affiliation: Department of Surgery, University of Melbourne, Austin Health Melbourne, Victoria, Australia.
authors.forename: Shir Lin
authors.initials: SL
authors.lastname: Koh
authors.forename: Joon Win
authors.initials: JW
authors.lastname: Tan
authors.forename: Vijayaragavan
authors.initials: V
authors.lastname: Muralidharan
authors.forename: Christopher
authors.initials: C
authors.lastname: Christophi