Prolonged effect of leukocytosis on reperfusion injury of rat intestine: real-time ATP change studied using (31)P MRS

Intestinal ischemia/reperfusion injury: defining the role of the gut microbiome

Intestinal ischemia/reperfusion (I/R) injury initiates a systemic inflammatory response syndrome with a high associated mortality rate. Early diagnosis is essential for reducing surgical mortality, yet current clinical biomarkers are insufficient. Metabonomics is a novel strategy for studying intestinal I/R, which may be used as part of a systems approach for quantitatively analyzing the intestinal microbiome during gut injury. By deconvolving the mammalian–microbial symbiotic relationship systems biology thus has the potential for personalized risk stratification in patients exposed to intestinal I/R. This review describes the mechanism of intestinal I/R and explores the essential role of the intestinal microbiota in the initiation of systemic inflammatory response syndrome. Furthermore, it analyzes current and future approaches for elucidating the mechanism of this condition.

CO-releasing molecules (CORM-2)-liberated CO attenuates leukocytes infiltration in the renal tissue of thermally injured mice

OBJECTIVE

To determine whether the CO-releasing molecule -liberated CO attenuates infiltration of leukocytes in the renal tissue of thermally injured mice.

MATERIALS AND METHODS

Twenty-eight mice were assigned to four groups. Mice in sham group (n=7) were underwent sham thermal injury, whereas mice in burn group (n=7) received 15% total body surface area (TBSA) full-thickness thermal injury. Mice in burn+CORM-2 group (n=7) underwent thermal injury followed by immediate administration of CORM-2 (8mg/kg, i.v.), whereas mice in burn+iCORM-2 group (n=7) underwent thermal injury followed by administration of iCORM-2 (an inactive compound used as negative control). Histological alterations and granulocytes infiltration in kidney were assessed alongised PMN accumulation, activation of NF-kBeta, expressions of ICAM-1 and HO-1 expression in renal tissues.

RESULTS

Treatment of thermally injured mice with CORM-2 significantly attenuated PMN accumulation and prevented activation of NF-kBeta in the kidney. This was accompanied by a decrease of the expression of ICAM-1 and an increase in HO-1 expression. In parallel, burn-induced granulocytes infiltration in renal tissue was markedly decreased by treatment with CORM-2.

CONCLUSIONS

CO delivered by CORM-2 attenuates leukocytes infiltration in the kidney of burned mice by interfering with NF-kBeta activation, protein expression of ICAM-1 and therefore suppressing endothelial cells pro-adhesive phenotype.

Carbon liberated from CO-releasing molecules attenuates leukocyte infiltration in the small intestine of thermally injured mice

AIM

To determine whether Carbon (CO) liberated from CO-releasing molecules attenuates leukocyte infiltration in the small intestine of thermally injured mice.

METHODS

Thirty-six mice were assigned to four groups. Mice in the sham group (n = 9) were underwent to sham thermal injury; mice in the burn group (n = 9) received 15% total body surface area full-thickness thermal injury; mice in the burn + CORM-2 group (n = 9) were underwent to the same thermal injury with immediate administration of tricarbonyldichlororuthenium (II) dimer CORM-2 (8 mg/kg, i.v.); and mice in the burn+DMSO group (n = 9) were underwent to the same thermal injury with immediate administration of 160 muL bolus injection of 0.5% DMSO/saline. Histological alterations and granulocyte infiltration of the small intestine were assessed. Polymorphonuclear neutrophil (PMN) accumulation (myeloperoxidase assay) was assessed in mice mid-ileum. Activation of nuclear factor (NF)-kappa B, expression levels of intercellular adhesion molecule-1 (ICAM-1) and inducible heme oxygenase in mid-ileum were assessed.

RESULTS

Treatment of thermally injured mice with CORM-2 attenuated PMN accumulation and prevented activation of NF-kappa B in the small intestine. This was accompanied by a decrease in the expression of ICAM-1. In parallel, burn-induced granulocyte infiltration in mid-ileum was markedly decreased in the burn mice treated with CORM-2.

CONCLUSION

CORM-released CO attenuates leukocyte infiltration in the small intestine of thermally injured mice by interfering with NF-kappa B activation and protein expression of ICAM-1, and therefore suppressing the pro-adhesive phenotype of endothelial cells.

Carbon liberated from CO-releasing molecules attenuates leukocyte infiltration in the small intestine of thermally injured mice

AIM: To determine whether Carbon (CO) liberated from CO-releasing molecules attenuates leukocyte infiltration in the small intestine of thermally injured mice.

METHODS: Thirty-six mice were assigned to four groups. Mice in the sham group (n = 9) were underwent to sham thermal injury; mice in the burn group (n = 9) received 15% total body surface area full-thickness thermal injury; mice in the burn + CORM-2 group (n = 9) were underwent to the same thermal injury with immediate administration of tricarbonyldichlororuthenium (II) dimer CORM-2 (8 mg/kg, i.v.); and mice in the burn+DMSO group (n = 9) were underwent to the same thermal injury with immediate administration of 160 μL bolus injection of 0.5% DMSO/saline. Histological alterations and granulocyte infiltration of the small intestine were assessed. Polymorphonuclear neutrophil (PMN) accumulation (myeloperoxidase assay) was assessed in mice mid-ileum. Activation of nuclear factor (NF)-κΒ, expression levels of intercellular adhesion molecule-1 (ICAM-1) and inducible heme oxygenase in mid-ileum were assessed.

RESULTS: Treatment of thermally injured mice with CORM-2 attenuated PMN accumulation and prevented activation of NF-κΒ in the small intestine. This was accompanied by a decrease in the expression of ICAM-1. In parallel, burn-induced granulocyte infiltration in mid-ileum was markedly decreased in the burn mice treated with CORM-2.

CONCLUSION: CORM-released CO attenuates leukocyte infiltration in the small intestine of thermally injured mice by interfering with NF-κΒ activation and protein expression of ICAM-1, and therefore suppressing the pro-adhesive phenotype of endothelial cells.

Disruption of P-selectin signaling modulates cell trafficking and results in improved outcomes after mouse warm intestinal ischemia and reperfusion injury

BACKGROUND

This study analyzes the role of T lymphocytes and neutrophils (PMN) in intestinal ischemia and reperfusion injury (IRI) using either P-selectin blockade or elimination.

METHODS

Using a model of severe mouse warm intestinal IRI, the following groups were performed: group 1: wild type C57BL6 no treatment; group 2: wild type treated with r-PSGL1-Ig; group 3: C57BL6 genetically deficient in P-selectin. Survival was assessed at day 7; intestine was assayed for histopathology, apoptosis, myeloperoxidase (MPO), inflammatory cytokines, hemoxygenase-1 (HO-1), and CD3 lymphocytes. Standard statistical comparison was undertaken.

RESULTS

The survival was significantly (P < 0.01) improved in the treatment groups: group 1, 50%; group 2, 90%; group 3, 100%. Graded histopathology and crypt apoptosis were improved in groups 2 and 3. MPO and CD3 positive cells were significantly reduced in groups 2 and 3. A significant reduction in inflammatory/Th1-type cytokines was seen in groups 2 and 3 as compared to group 1. Conversely, a significant increase in Th2-type cytokines and HO-1 production was seen selectively in groups 2 and 3.

CONCLUSIONS

This study demonstrates the importance of P-selectin signaling in warm, murine intestinal IRI in that either the blockade of or the genetic deficiency in P-selectin confers a survival advantage and reduction in tissue injury/inflammation. The mechanism involves a reduction of PMN and CD3 T cell infiltration and an alteration in the cytokine microenvironment in favor of a Th2 profile. These data implicate T lymphocyte as an important regulatory cell in this inflammatory process.

Xanthine oxidase and activated neutrophils cause oxidative damage to skeletal muscle after contractile claudication

We previously showed oxidative damage and edema within skeletal muscle after contractile claudication. To investigate the sources of this oxidative damage in the gastrocnemius muscle, we administered allopurinol (Allo, to inhibit xanthine oxidase) and cyclophosphamide (Cyclo, to deplete neutrophils) before inducing contractile claudication in male Sprague Dawley rats. Contractile claudication (ligated stimulated, LS) caused a significant increase in xanthine oxidase activity [sham ligated stimulated (SS) = 2.57 +/- 0.07; LS = 3.22 +/- 0.07] and neutrophil infiltration (SS = 0.47 +/- 0.03; LS = 0.91 +/- 0.10) compared with controls (SS), and this was associated with increased lipid peroxidation, protein oxidation, muscle damage, and edema. Pretreatment with Allo attenuated the increase in xanthine oxidase activity and attenuated lipid hydroperoxides (control LS = 12.85 +/- 0.50; Allo LS = 9.96 +/- 0.71), muscle damage, and neutrophil infiltration (control LS = 0.91 +/- 0.10; Allo LS = 0.61 +/- 0.07). This latter finding suggests that xanthine oxidase-derived oxidants are chemotactic to neutrophils. Pretreatment with Cyclo reduced neutrophil infiltration (control LS = 0.91 +/- 0.10; Cyclo LS = 0.55 +/- 0.02) and attenuated lipid peroxidation (control LS = 12.85 +/- 0.50; Cyclo LS = 6.462 +/- 0.62), protein oxidation (control LS = 2.59 +/- 0.47; Cyclo LS = 1.77 +/- 0.60), muscle damage, and edema. Together, these data indicate that contractile claudication causes an increase in xanthine oxidase activity and neutrophils in muscle and that inhibition of these oxidant sources protects against oxidative stress, muscle damage, and edema.

Evaluation of intestinal intramucosal pH, arterial and portal venous blood gas values, and intestinal blood flow during small intestinal ischemia and reperfusion in dogs

OBJECTIVES

To determine whether small intestinal ischemia and reperfusion affects intestinal intramucosal pH (pHi), arterial and portal venous blood gas values, and intestinal blood flow (IBF) and to investigate relationships between regional intestinal tissue oxygenation and systemic variables in dogs.

ANIMALS

15 healthy adult Beagles.

PROCEDURE

Occlusion of superior mesenteric artery (SMA) for 0, 30, or 60 minutes, followed by reperfusion for 180 minutes, was performed; IBF, pHi, arterial and portal venous blood gas values, arterial pressure, and heart rate were measured at various time points; and intestinal mucosal injury was histologically graded.

RESULTS

Occlusion of the SMA induced significant decreases in pHi and IBF. After the release of the occlusion, IBF returned rapidly to baseline values, but improvement in pHi was slow. Arterial and portal venous blood gas analyses were less sensitive than tonometric measurements of pHi, and there was no correlation between results of blood gas analyses and tonometric measurements. Histologic score for intestinal mucosal injury increased significantly, depending on duration of ischemia, and there was a correlation between tonometric results and the histologic score.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that it is difficult to accurately evaluate local oxygenation disorders by monitoring at the systemic level, whereas clinically pHi is the only reliable indicator of inadequate regional intestinal tissue oxygenation in dogs.