BackgroundPortal vein ligation (PVL) combined with in situ splitting (ISS) has been shown to induce remarkable liver regeneration in patients. The purpose of this study was to establish a model of PVL+ISS in rats for exploring the possible mechanisms of liver regeneration using these techniques.Materials and MethodsRats were randomly assigned to three experimental groups: selective PVL, selective PVL+ISS and sham operation. The hepatic regeneration rate (HRR), Ki-67, liver biochemical determinations and histopathology were assessed at 24, 48, and 72 h and 7 days after the operation. The microcirculation of the median lobes before and after ISS was examined by laser speckle contrast imaging. Meanwhile, cytokines such as TNF-α, IL-6, HGF and HSP70 in regenerating liver lobes at 24 h was investigated by RT-PCR and ELISA.ResultsThe HRR of PVL+ISS was much higher than that of the PVL at 72 h and 7 days after surgery (p<0.01). The expression of Ki-67 in hepatocytes in the regenerating liver lobe was stronger in the PVL+ISS group than in the PVL group at 48 and 72 h (p<0.01). There was a significant reduction in microcirculation blood perfusion of the left median lobe before and after ISS. Liver biochemical determinations and histopathology demonstrated more severe hepatocyte injury in the PVL+ISS group. Both the mRNA levels of TNF-α and IL-6 and the protein levels of TNF-α, IL-6 and HGF in regenerating liver lobes were higher in the PVL+ISS than the PVL alone.ConclusionsThe higher HRR in the PVL+ISS compared with the PVL confirmed that we had successfully established a PVL+ISS model in rats. The possible mechanisms included the reduced microcirculation blood perfusion of the left median lobe and up-regulation of cytokines in the regenerating lobes after ISS.

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Preserving duodenal-jejunal transit does not impede glucose tolerance and diabetes remission after gastric bypass in type-2 diabetes Sprague-Dawley rat model.

Recent studies suggest the possibility of the stomach playing a role in diabetes remission after bariatric surgery. In this study, we investigated whether bypassing the stomach alleviates diabetes in diabetic rodent model. Eighteen moderately obese and diabetic Sprague-Dawley rats were randomly assigned to Esophagoduodenostomy with or without gastric preservation (EDG and EDNG/total gastrectomy, respectively), and SHAM groups. Bodyweight, food intake, fasting glucose level, oral glucose tolerance test result (OGTT), and hormone levels (insulin, glucagon-like peptide-1, ghrelin, gastrin and glucagon) were measured preoperative and postoperatively. Postoperatively, bodyweight and food intake did not differ significantly between the EDG and EDNG groups. Postoperative fasting blood glucose and OGTT results declined significantly in the EDG and EDNG group when compared with the respective preoperative levels. Postoperative glucose control improvements in EDNG group was significantly inferior when compared to EDG. Compared preoperatively, postoperative plasma ghrelin and gastrin levels declined significantly in EDNG group. Preoperative and postoperative plasma GLP-1 level did not differ significantly among all the groups. Postoperatively, EDG group had significantly higher insulin and lower glucagon levels when compared with SHAM. In conclusion, bypassing and preserving the stomach resulted in superior glucose control improvements than total gastrectomy.

Background: To observe if absorbable suture can effectively and safely be used to close the mesenteric defect after Roux-en-Y reconstruction. Methods: Rats were randomly assigned to 5 experimental groups according to different suture materials used in closing the mesenteric defects (Peterson’s space) after Roux-en-Y gastric bypass. Group A (control group), Group B (non-absorbable suture, Prolene suture), Group C (biological glue), Group D (non-absorbable suture, polyester suture) and Group E (absorbable suture). All rats were followed up for 8 weeks postoperatively and underwent laparotomy to observe the degree of adhesion and closure of the mesenteric defect. Results: No significant difference was found in the decrease in food intake and body weight among all groups. No internal hernia (IH) occurred in any group. The mesenteric defects of Group A remained completely visible without any closure or adhesion. Multiple gaps were found between Prolene suture and the mesentery along the suture line in Group B. The mesenteric defects of Group C were complete closed with multiple adhesions of the small intestine and the greater omentum. The mesenteric defects had closed completely in both Group D and Group E. Average adhesion score of Group A and Group B was 0 and 0.33±0.52 respectively. Average adhesion score was higher in group C (3.83±0.41) than the other groups (p＜0.05). Group D and E had similar average adhesion score, 3.17±0.41 and 3.00±0.00 respectively. Conclusion: Absorbable sutures can be effectively and safely used to close the mesenteric defect in a rat model.