title: Effects of perioperative hypothermia and reactive oxygen species in the healing of colonic anastomosis in rats.
abstract: OBJECTIVE
  We evaluated the hypothesis that induced perioperative hypothermia (32 ± 1ºC) affects the redox balance in the tissue of colonic anastomosis in rats by modifying biochemical enzymatic and non-enzymatic markers related to oxidative stress.
  
  
  METHODS
  Forty-eight male Wistar rats were randomly divided into eight experimental groups of six animals each and underwent laparotomy, sigmoid section and immediate anastomosis. Four groups were operated under normothermia (36 ± 1ºC), and the other four under hypothermia (32 ± 1ºC). The animals were reoperated on days 3, 7 and 14 postoperatively, and two groups underwent SHAM at 3 days. From the scar tissue samples, the activity of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) was evaluated, and the levels of non-enzymatic markers of oxidative stress, such as reduced glutathione (GSH) and lipid peroxidation, were measured by the thiobarbituric acid reactive substances (TBARS) assay. The means were compared between groups corresponding to each day of sampling and euthanasia.
  
  
  RESULTS
  The hypothermic groups showed a significant reduction on the activity of SOD on day 7 postoperatively, on the activity of CAT on days 7 and 14 postoperatively and on the levels of GSH on day 7 postoperatively. The level of lipid peroxidation was increased in the hypothermia group on day 7 postoperatively and decreased on day 14 compared with the normothermic groups.
  
  
  CONCLUSIONS
  Perioperative hypothermia reduced the activity of the antioxidant enzymes catalase and superoxide dismutase, glutathione levels and increased lipid peroxidation in the scar tissue of colonic anastomoses in rats.
authors.affiliation: Department of Surgery, Federal University of Santa Catarina, Florianopolis, SC, Brazil.
authors.forename: João Carlos Costa de
authors.initials: JC
authors.lastname: Oliveira
authors.affiliation: University of Southern Santa Catarina, Palhoça, SC, Brazil.
authors.forename: Camila Helena de
authors.initials: CH
authors.lastname: Oliveira
authors.affiliation: University of Southern Santa Catarina, Palhoça, SC, Brazil.
authors.forename: Henrique Eduardo de
authors.initials: HE
authors.lastname: Oliveira
authors.affiliation: Center for Agricultural Sciences, UFSC, Florianopolis, SC, Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Pereira
authors.affiliation: Center for Agricultural Sciences, UFSC, Florianopolis, SC, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Maraschin
authors.affiliation: Department of Surgery, UFSC, Florianopolis, SC, Brazil.
authors.forename: Armando José
authors.initials: AJ
authors.lastname: d'Acâmpora
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D002374:Catalase / Q000378:metabolism; D003106:Colon / Q000201:enzymology / Q000601:surgery*; D005978:Glutathione / Q000378:metabolism; D007036:Hypothermia, Induced / Q000009:adverse effects*; D015227:Lipid Peroxidation; D008297:Male; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology; D011184:Postoperative Period; D011897:Random Allocation; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism; D013997:Time Factors; D014945:Wound Healing / Q000502:physiology*
chemical_list: D017382:Reactive Oxygen Species; D002374:Catalase; D013482:Superoxide Dismutase; D005978:Glutathione