title: [The timing of infusion of hypertonic saline to exert protective effect on intestinal barrier function in the rabbit with intestinal ischemia/reperfusion injury].
abstract: OBJECTIVE
  To study the timing of infusion of hypertonic saline solution (HTS) to exert its protective effect on intestinal barrier function in rabbits with intestinal ischemia/reperfusion (I/R) injury.
  
  
  METHODS
  Seventy-two rabbits were randomly divided into four groups (each n=18): sham operation group, I/R group, HTS pretreatment group and HTS delayed treatment group. The intestinal I/R models were produced by blocking the superior mesenteric artery (SMA) for 1 hour followed by release of the SMA. 7.5% HTS (6 ml/kg) was infused in HTS pretreatment group 5 minutes before release of SMA, and HTS was infused in delayed treatment group 2 hours after reperfusion and finished in 5 minutes. Levels of D-lactic acid (D-Lac), lipopolysaccharide (LPS), tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) were determined before ischemia and 2, 4, 6 hours after reperfusion. The levels of malonaldehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO) in intestinal tissues of 8 rabbits in each group were measured at 6 hours after reperfusion. Meanwhile the intestinal morphological changes were observed, and the Chin score, which reflected the degree of injury to intestinal mucosa was calculated.
  
  
  RESULTS
  Compared with sham operation group, D-Lac, LPS, TNF-α and IL-10 in I/R group were significantly increased from 2 hours after reperfusion (D-Lac: 18.91 ± 3.46 mg/L vs. 3.92 ± 0.61 mg/L, LPS: 869 ± 85 EU/L vs. 422 ± 27 EU/L, TNF-α: 23.80 ± 4.22 μg/L vs. 3.65 ± 0.51μg/L, IL-10: 8.90 ± 2.75 μg/L vs. 2.53 ± 0.80 μg/L, all P<0.05); MDA, MPO and Chiu score were significantly increased (MDA: 398 ± 28 nmol/mg vs. 173 ± 20 nmol/mg, MPO: 465 ± 52 mU/mg vs. 183 ± 25 mU/mg, Chiu score: 4.36 ± 0.52 vs. 0.38 ± 0.22, all P<0.05), while SOD decreased significantly (35 ± 9 U/mg vs. 52 ± 8 U/mg, P<0.05). Compared with I/R group, the levels of D-Lac, LPS, TNF-α, MDA, MPO and Chiu score in HTS pretreatment group were lower (D-Lac: 11.45 ± 0.92 mg/L vs. 18.91 ± 3.46 mg/L, LPS: 455 ± 114 EU/L vs. 869 ± 85 EU/L, TNF-α: 10.32 ± 2.11 μg/L vs. 23.80 ± 4.22 μg/L, MDA: 221 ± 21 nmol/mg vs. 398 ± 28 nmol/mg, MPO: 271 ± 20 mU/mg vs. 465 ± 52 mU/mg, Chiu score: 1.69 ± 0.24 vs. 4.36 ± 0.52, all P<0.05), while IL-10 and SOD were significantly increased (IL-10: 14.54 ± 2.02 μg/L vs. 8.90 ± 2.75 μg/L, SOD: 90 ± 14 U/mg vs. 35 ± 9 U/mg, both P<0.05). The levels of the above indexes in HTS delayed treatment group were similar to I/R group, and the effect was lower than that in HTS pretreatment group.
  
  
  CONCLUSIONS
  HTS had the protective effect on intestine suffering from I/R injury. But the protective effect was time dependent, and early treatment shows protective effect.
authors.affiliation: Department of Emergency Medicine, Peking Union Medical College Hospital, Beijing 100730, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.forename: Liang-liang
authors.initials: LL
authors.lastname: Zheng
authors.forename: Lu
authors.initials: L
authors.lastname: Liang
authors.forename: Ye-cheng
authors.initials: YC
authors.lastname: Liu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.forename: Teng-da
authors.initials: TD
authors.lastname: Xu
authors.forename: Hua-dong
authors.initials: HD
authors.lastname: Zhu
authors.forename: Zhong
authors.initials: Z
authors.lastname: Wang
authors.forename: Xue-zhong
authors.initials: XZ
authors.lastname: Yu
authors.forename: Sui
authors.initials: S
authors.lastname: Ma
mesh_terms: D000818:Animals; D005260:Female; D016753:Interleukin-10 / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D007422:Intestines / Q000187:drug effects* / Q000473:pathology; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D011817:Rabbits; D015427:Reperfusion Injury / Q000473:pathology*; D012462:Saline Solution, Hypertonic / Q000494:pharmacology*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D012462:Saline Solution, Hypertonic; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D019344:Lactic Acid