Exogenous recombinant adiponectin improves survival in experimental abdominal sepsis.

BACKGROUND: Adiponectin, which has anti-inflammatory features, is an important substance in several metabolic mechanisms. AIMS: The aim of this study is to evauate the effects of exogenous intraperitoneal administration of adiponectin on the survival, intrabdominal adhesion and inflammatory cytokine levels in an experimental sepsis model. STUDY DESIGN: Animal experimentation. METHODS: Ninety rats were divided into a control group, adiponectin group and sham group. A cecal puncture abdominal sepsis model was performed in the adiponectin and control groups. Every three hours, exogenous adiponectin was administrated to the adiponectin group. At the 3(rd) and 24(th) hours, 10 rats were sacrified in each group in order to measure plasma tumor necrosis factor-α (TNF-α), interleukin (IL) 10, soluble intracellular adhesion molecule (ICAM)-1, IL-6 and macrophage inhibitory factor levels, and the activity of nuclear factor (NF)-kB. The remaining rats were followed for survival. RESULTS: The plasma levels of TNF-α, soluable ICAM-1, IL-6, and macrophage inhibitory factor were significantly higher in the control group than in the adiponectin and sham group (p<0.05). The increase in inflammatory cytokines with time was more prominent in the control group. The activity of NF-kB in the control group was higher than in the adiponectin group (p<0.05). The survival rate of the adiponectin group was higher than in the control group. CONCLUSION: Administration of exogenous adiponectin to the peritoneum in abdominal sepsis increased survival and decreased intrabdominal adhesions by decreasing the inflammatory response.

The effect of erythropoietin on anastomotic healing of irradiated rats.

AIM: The aim of the present study is to evaluate the possible protective effects of erythropoietin (EPO) on anastomotic wound healing after preoperative radiotherapy according to its pleiotropic mechanism of action. METHODS: Thirty-two male Wistar albino rats were randomized into four groups containing eight rats each: ANAS group, standard resection plus anastomosis; RT+ANAS group, radiation plus standard resection plus anastomosis; ANAS+EPO group, standard resection plus anastomosis plus EPO; RT+ANAS+EPO, radiation plus standard resection plus anastomosis plus EPO. All animals were sacrificed by cardiac puncture, and anastomotic healing was measured by bursting pressure, hydroxyproline (OHP) levels, myeloperoxidase (MPO) activity and histopathological evaluations. Malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α), and matrix metalloproteinase-9 (MMP-9) were also measured in serum specimens. RESULTS: OHP levels in the RT+ANAS + EPO group were significantly increased compared with other groups (p < .05). In contrast, MPO activity in the RT+ANAS+EPO group was significantly decreased compared with other groups (p < .05). Serum MDA levels were found to be decreased in the ANAS+EPO and RT+ANAS+EPO groups (p < .05). Group comparisons demonstrated that bursting pressure was significantly higher in EPO treated rats (p < .05). The histopathology results revealed that EPO treatment improves anastomotic wound healing though decreased necrosis and inflammatory cell infiltration and increased fibroblast activity. CONCLUSION: The findings of the present study indicate that EPO contributes to wound healing and the strength of colon anastomosis following radiation due to its antioxidant and anti-inflammatory effects, but further studies are needed to explore the significance of these effects.

N-acetyl-cysteine improves anastomotic wound healing after radiotherapy in rats.

AIM: This study was designed to determine the effects of intraperitoneally or orally administered N-acetylcysteine (NAC) on anastomotic healing of irradiated rats. METHODS: Thirty-two male Wistar albino rats were randomized into four groups containing 8 rats each: I; standard resection plus anastomosis, II; radiation plus standard resection plus anastomosis, III; radiation plus standard resection plus anastomosis plus oral NAC, IV; radiation plus standard resection plus anastomosis plus intraperitoneal NAC. Four types of assessment were performed: bursting pressure, hydroxiproline (OHP) content, histopathology, and biochemical evaluation, including serum malondialdehyde (MDA), advanced oxidation protein products (AOPP), reduced glutathione (GSH) and superoxide dismutase (SOD) activities. RESULTS: Group comparisons demonstrated that bursting pressure was significantly higher in NAC treated rats. The mean tissue OHP concentration in the anastomotic tissue was significantly lower in irradiated rats (group II) than in the other groups. NAC treatment caused increased activity of SOD and GSH. In contrast, MDA levels were found to be decreased in groups III and IV. Histopathological analysis revealed that NAC administration, either orally or intraperitoneally, leads to a better anastomotic healing in terms of reepithelialization, perianastomotic fibrosis, ischemic necrosis, and muscle layer destruction. CONCLUSION: The present study supports the hypothesis that NAC administration alleviates the negative effects of radiotherapy on anastomotic healing. Nevertheless, the underlying mechanisms responsible for this protective effect is unknown today.