| Part I:Establishment and evaluation of a precise peritoneal adhesion model after surgeryObjective:To create an accurate postoperative model of postoperative peritoneal adhesion and to evaluate it.Methods:In this study,a rat model of peritoneal adhesion was established by laparotomy.The specific surgical procedure was:anesthesia was performed by intraperitoneal injection using sterile 10%chloral hydrate.In order to avoid the violent reaction of the rats in the operation,the rats'limbs have no spontaneous movement as an indicator of satisfactory anesthesia.Along the middle of the rat's abdomen,the opening was 4 cm,and the skin and muscles were cut in turn to enter the abdominal cavity.Fully expose the cecum,and scrape the cecum 40 times with sterile gauze at the3 cm above the blind end of the cecum to the cecal point-like hemorrhage.The scratch area is 1×2 cm~2,and the number of bleeding points is counted.The abdominal wall was scraped with a surgical blade on the side of the abdominal wall corresponding to the cecum,and the area of scratching was 1×2 cm~2.On the 7th day after the operation,the rats were sacrificed by excessive anesthesia.The"U"incision was opened to the abdominal cavity of the rats to observe the abdominal adhesion and the mortality of the rats.The degree of peritoneal adhesion was evaluated by the adhesion ratio index,that is,the adhesion ratio=adhesion area./Damage area.Results:The statistical results of intraoperative cecal bleeding were 11.5±1.5.The postoperative mortality was 0%.The mean adhesion of postoperative rats was 0.69.Conclusion:The established model of postoperative peritoneal adhesion in rats has low mortality and can effectively control the formation and stability of rat peritoneal adhesions.The stability of the number of cecal bleeding points indicates the consistency of the degree of cecal injury in rats,and the quantitative evaluation index ensures the accuracy of the model.Part II: Study on the use of sericin to prevent/reduce peritoneal adhesionsObjective: To explore the application of sericin in preventing/reducing peritoneal adhesionsMethods: In this part of the study,silkworm cocoons were firstly used to extract sericin by high-temperature alkaline extraction to obtain sericin solution.The sericin solution was applied to the above-mentioned precise rat model of peritoneal adhesion,and normal saline and commercial medicine were used.Chitosan was used as a control.The rat peritoneal adhesions were observed at the corresponding time points,and the peritoneal adhesions were excised.On the one hand,the rat adhesion tissue specimens were fixed,paraffin embedded,and sectioned for H&E staining.On the other hand,the rat adhesion tissues were observed.Molecules(including IL-6,PAI-1,TGF-?1),which play an important role in the peritoneal adhesion,detect the mRNA expression level.Results: The degree of peritoneal adhesion in the sericin solution group was significantly lower than that in the saline group and the chitosan group.The inflammatory degree of the peritoneal adhesion area in the sericin solution group was significantly lower than that in the saline group and the medical chitosan group.The expression of IL-6 mRNA in the peritoneal adhesions of the sericin solution group was significantly lower than that of the saline group and the chitosan group.The expression of PAI-1 mRNA in the peritoneal adhesions of the sericin solution group was obvious.The expression level of TGF-?1 mRNA in the peritoneal adhesion tissue of the sericin solution group was significantly lower than that of the normal saline group and the medical chitosan group.Conclusion: Sericin solution can effectively prevent/reduce the formation of rat peritoneal adhesion by reducing the inflammatory reaction in the area of peritoneal injury and promoting fibrinolysis.It can be used as a material for anti-peritoneal adhesion. |
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