[Effect of unfractionated heparin on the expression of heme oxygenase-1 in intestinal mucosa of mice with sepsis].

Objective: To investigate the effect of unfractionated heparin (UFH) on the expression of heme oxygenase-1 (HO-1) in intestinal mucosa of mice with sepsis.

Methods: Thirty-six male C57BL/6J mice were randomly divided into sham group, cecal ligation and puncture (CLP) group and UHF group, n =12 in each group. Model of intestinal injury in sepsis was induced by CLP. In sham group, the mice were exposed without ligation of cecum. In UFH group, the mice were treated intravenously with 8 U of UFH via the tail vein half an hour before the operation and 12 hours after the surgery respectively. Six mice in each group were randomly chosen at 4 hours and 24 hours after operation to collect inferior vena venous blood samples and terminalileum tissues. The serum levels of interleukins (IL-1 β,IL-6),and tumor necrosis factor-α (TNF-α) were determined by enzyme linked immunosorbent assay (ELISA).The serum level of D-lactate was determined by colorimetry.Pathological changes of ileum tissue and Chiu score were observed after hematoxylin eosin (HE) staining. The HO-1 expression was detected immunohistochemically.

Results: In sham group, no significant changes in the serum levels of IL-1 β,IL-6,TNF-α and D-lactate were observed. Twenty-four hours after the operation, the structure of intestinal mucosa was basically normal without obvious pathology change and no HO-1 positive cells were found. The serum levels of IL-1 β,IL-6,TNF-α,and D-lactate in CLP group were gradually increased, and they were significantly increased as compared with sham group [IL-1 β (ng/L):40.87±2.88 vs.22.60±2.05 at 4 hours,113.73±3.96 vs.22.07±2.74 at 24 hours;IL-6 (ng/L):63.89±3.26 vs.44.89±3.38 at 4 hours,176.56±5.45 vs.45.76±4.02 at 24 hours; TNF-α (ng/L):194.62± 14.13 vs.152.05±6.22 at 4 hours,599.62± 10.20 vs.155.90± 14.18 at 24 hours; D-lactate (mmol/L):0.24± 0.02 vs.0.19 ± 0.01 at 4 hours,0.33 ± 0.04 vs.0.20 ± 0.02 at 24 hours, all P ＜ 0.05].Twenty-four hours after the operation, edema and inflammation in ileal mucosa, intestinal villi structural damage were observed, the Chiu score was significantly higher than those in the sham group [4.5 (3.0-5.0) vs.0 (0-1.0),P ＜ 0.05],and a small amount of HO-1 positive cells were localized in the intestinal mucosa. Compared with CLP group, the serum levels of IL-1 β,IL-6,TNF-α,and D-lactate of UFH group were significantly decreased [IL-1 β (ng/L):31.53 ± 2.90 vs.40.87 ± 2.88 at 4 hours,61.13 ± 2.80 vs.113.73 ± 3.96 at 24 hours;IL-6 (ng/L):51.16 ± 5.68 vs.63.89 ± 3.26 at 4 hours,81.16 ± 4.54 vs.176.56 ± 5.45 at 24 hours; TNF-α (ng/L):171.76± 5.60 vs.194.62± 14.13 at 4 hours,328.48 ± 10.79 vs.599.62± 10.20 at 24 hours; D-lactate (mmol/L):0.21 ±0.01 vs.0.24±0.02 at 4 hours,0.24±0.02 vs.0.33±0.04 at 24 hours, all P ＜ 0.05]. Twenty-four hours after the operation, intestinal injury was ameliorated, the Chiu score was significantly lower [1.5 (1.0-5.0) vs.4.5 (3.0-5.0),P ＜ 0.05],and HO-1 positive cells in the intestinal mucosa was remarkably increased.

Conclusion: UFH can enhance the expression of HO-1 in intestinal mucosa, reduce the release of inflammatory factors, ameliorate the intestinal inflammatory response, and thus play a protective role in intestinal tissue in mice with sepsis.