title: Effect of 100% oxygen on E-selectin expression, recruitment of neutrophils and enterocyte apoptosis following intestinal ischemia-reperfusion in a rat.
abstract: Recent evidence suggests that neutrophil recruitment may initiate cell apoptosis in ischemic tissues. We have recently shown that enterocyte apoptosis is increased following intestinal ischemia-reperfusion (IR) injury. The purpose of the present study was to examine the effect of hyperoxia on E-selectin expression, neutrophil recruitment and enterocyte apoptosis following intestinal IR in a rat. Male Sprague-Dawley rats were divided into three experimental groups: (1) sham rats underwent laparotomy without vascular occlusion and were ventilated with air (Sham) (2) IR rats underwent occlusion of both the superior mesenteric artery and portal vein for 30 min and were ventilated with air (IR), and (3) IR-O2 rats underwent IR and were ventilated with 100% started 10 min before reperfusion and continued for 6 h (IR-O2). Intestinal structural changes were determined 24 h following IR. Immunohistochemistry for E-selectin (using E-selectin cleaved concentrated polyclonal antibody) was performed to identify E-selectin immunoreactivity localized to the endothelium of venules. The recruitment of neutrophils was calculated per 100 venules. Immunohistochemistry for Caspase-3 was performed for identification of apoptotic cells. Non-parametric one-way ANOVA test was used for statistical analysis with p less than 0.05 considered statistically significant. A significant increase in E-selectin expression in the jejunum (6.1 +/- 2.2 vs. 2.5 +/- 1.0 E-selectin positive vessels/100 vessels, p < 0.05) and ileum (12.1 +/- 2.7 vs. 3.3 +/- 1.2 E-selectin positive vessels/100 vessels, p < 0.05) and a concomitant increase in neutrophil recruitment in the ileum (5.5 +/- 1.6 vs. 1.3 +/- 0.6 adhered PMN's per 100 venules) were observed in IR rats compared to sham animals and were accompanied by increased cell apoptosis (p < 0.05). Treatment with 100% oxygen resulted in a significant attenuation in E-selectin expression in the ileum (2.7 +/- 1.1 vs. 12.1 +/- 2.7 E-selectin positive vessels/100 vessels, p < 0.05), and neutrophil recruitment in the jejunum (2.5 +/- 1.4 vs. 7.7 +/- 1.9 adhered PMN's per 100 venules, p < 0.05) and ileum (1.5 +/- 0.7 vs. 5.5 +/- 1.6 adhered PMN's per 100 venules, p < 0.05) compared to IR animals, and was accompanied by decreased cell apoptosis (p < 0.05). Hyperoxia inhibits enterocyte apoptosis following intestinal ischemia-reperfusion. Down-regulation of E-selectin expression with subsequent decrease in neutrophil recruitment may be responsible for this effect.
authors.affiliation: Department of Pediatric Surgery, Bnai Zion Medical Center, The Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, 47 Golomb St, POB 4940, Haifa, Israel. igor-dr@internet-zahav.net
authors.forename: Igor
authors.initials: I
authors.lastname: Sukhotnik
authors.forename: Arnold G
authors.initials: AG
authors.lastname: Coran
authors.forename: Robert
authors.initials: R
authors.lastname: Greenblatt
authors.forename: Vera
authors.initials: V
authors.lastname: Brod
authors.forename: Jorge
authors.initials: J
authors.lastname: Mogilner
authors.forename: Eitan
authors.initials: E
authors.lastname: Shiloni
authors.forename: Ron
authors.initials: R
authors.lastname: Shaoul
authors.forename: Haim
authors.initials: H
authors.lastname: Bitterman
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002452:Cell Count; D004195:Disease Models, Animal; D019040:E-Selectin / Q000096:biosynthesis*; D020895:Enterocytes / Q000187:drug effects / Q000473:pathology*; D007082:Ileum / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007583:Jejunum / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology; D008297:Male; D009504:Neutrophils / Q000187:drug effects / Q000473:pathology*; D010100:Oxygen / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology
chemical_list: D019040:E-Selectin; D010100:Oxygen