【作者】 张群；

【导师】 于健春； 康维明； 朱广瑾；

【作者基本信息】 中国协和医科大学 ， 外科学， 2008， 博士

【摘要】 第一部分腹部手术后胃肠动力障碍动物模型的建立及其发生机制的研究研究背景:腹部手术后早期胃肠动力障碍,是胃肠道手术后常见的现象,严重时可导致麻痹性肠梗阻,增加感染及再手术风险,增加住院时间及医疗费用等。以往研究认为,腹部手术后早期胃肠动力障碍的主要机制在于:手术刺激造成体内致炎细胞因子释放增加、神经-内分泌激素调节机制作用等;为此,我们进行的前期动物实验证实,腹部手术后早期糖皮质激素干预可减少细胞炎性因子的释放、促进术后胃肠动力障碍恢复。但是由于糖皮质激素本身的副作用,其术后早期临床应用目前仍存在争议。因此,需要建立腹部手术后胃肠动力障碍动物模型,为进一步探讨其发生机制及干预措施奠定基础。研究目的:建立腹部手术后胃肠动力障碍动物模型,研究腹部手术创伤后炎性细胞因子释放、神经.内分泌激素调节变化在胃肠功能障碍的可能作用机制。研究方法:Wistar雄性大鼠24只,体重250±20g,随机分为正常对照组(n=6)、手术组(n=18)。手术组通过大鼠开腹手术,进行胃造口置管及部分盲肠切除术,建立腹部手术创伤模型。再按采取标本时间分成三组:术后24h组、术后72h组及术后6d组,每组6只。大鼠行开腹部分盲肠切除+胃造口术后第24h、72h、6天分别测定胃排空率或小肠推进率,同时心脏取血测定血清胃泌素、胃动素、IL-1、IL-6、TNF-α、Cox-2水平。研究结果:1.大鼠腹部手术创伤后,24h及72h胃排空率及小肠推进率较对照组明显降低(P＜0.01),以术后24h抑制最明显,术后72h逐渐恢复,到术后6d达到术前水平。而术后6d胃排空率及小肠推进率较对照组无明显差别。表明大鼠腹部手术创伤后24h-72h,胃肠动力抑制作用最为明显,术后6d已恢复到术前水平。2.大鼠腹部手术创伤后24h、72h血清IL-1、IL-6、TNF-α、Cox-2水平较对照组明显升高(P＜0.01),以术后24h-72h升高最明显,以后逐渐恢复,到术后6d达术前水平。表明大鼠腹部手术创伤后24h、72h血清IL-1、IL-6、TNF-α等炎症因子及Cox-2水平的明显升高,加重炎症反应,抑制胃肠动力,而术后6d逐步恢复到术前水平。3.大鼠腹部手术创伤后24h、72h血清胃泌素、胃动素水平较对照组明显降低(P＜0.01),以后逐渐恢复,术后6d达术前水平。表明大鼠腹部手术创伤后24h-72h血清胃泌素、胃动素等胃肠激素水平的明显降低,抑制胃肠动力,术后72h至6d逐步恢复到术前水平。结论:腹部手术创伤后24-72h胃肠动力受到明显抑制,其抑制程度与血清IL-1、IL-6、TNF-α、COX-2水平升高,胃动素水平下降密切相关。胃泌素水平仅在术后24h抑制最明显,术后72h-6d逐渐恢复到正常水平。第二部分ω-3脂肪乳剂对腹部手术创伤后胃肠功能障碍的干预对照研究研究背景:腹部手术后早期胃肠动力障碍,是胃肠道手术后常见的现象,严重时可导致麻痹性肠梗阻,增加感染及再手术风险,增加住院时间及医疗费用等。以往研究认为,腹部手术后早期胃肠动力障碍的主要机制在于:手术刺激造成体内致炎细胞因子释放增加、神经-内分泌激素调节机制作用等;为此,我们进行的前期动物实验证实,腹部手术后早期糖皮质激素干预可减少细胞炎性因子的释放、促进术后胃肠动力障碍恢复。但是由于糖皮质激素本身的副作用,其术后早期临床应用目前仍存在争议。我们在已建立了腹部手术后胃肠动力障碍动物模型及探讨其机制的基础上,对干预措施及效果进行研究。由于腹部及胃肠手术后,病人胃肠功能受到抑制,在相当一段时间内需胃肠减压、不能正常进食,肠外营养或肠内营养支持成为必要的支持治疗手段。近年来,ω-3脂肪乳剂作为肠外营养脂肪乳制剂之一,已在国内外临床应用。由于其独特的化学结构特点及其对病理生理调节特性,使ω-3脂肪乳剂在抗炎、抗凝、抗肿瘤、降血脂等方面,成为国内外研究的热点。但对手术后应用ω-3脂肪乳剂在减轻和调节炎症反应、促进胃肠动力功能的恢复方面的干预研究尚无报道,为此,我们进行了随机、对照性的动物实验研究。研究目的:ω-3脂肪乳剂对大鼠腹部手术后血清炎症因子、血清胃肠激素水平及胃肠动力功能的影响。研究方法:Wistar雄性大鼠54只,体重250±20g,随机分为生理盐水组(n=18),中长链脂肪乳组(n=18)及ω-3脂肪乳组(n=18)。每组再按术后采取标本时间分成术后24h组、术后72h组及术后6d组,每组6只。干预治疗:大鼠行开腹部分盲肠切除+胃造口术后1-6d分别通过胃造瘘管给予生理盐水(12.5ml/d)、10%中长链脂肪乳(12.5ml/d,5g/kg·d),10%ω-3脂肪乳组(12.5ml/d,5g/kg·d)。术后第1、3、6天分别测定胃排空率或小肠推进率,同时心脏取血测定血清胃泌素、胃动素、IL-1、IL-6、TNF-α、Cox-2水平。研究结果:1.ω-3脂肪乳剂组:在大鼠腹部手术创伤后72h,胃排空率及小肠推进率均明显高于生理盐水组、中长链脂肪乳剂组(P＜0.01);术后24h、第6d,ω-3脂肪乳剂组与生理盐水组、中长链脂肪乳剂组相比,上述指标无明显差别。表明与生理盐水、中长链脂肪乳剂干预相比,大鼠开腹手术后经胃造瘘给予ω-3脂肪乳剂在72h后有明显促进胃肠动力恢复的效果。2.ω-3脂肪乳剂组:在大鼠腹部手术创伤后72h,血清IL-1、IL-6、TNF-α、Cox-2水平均明显低于生理盐水及中长链脂肪乳组(P＜0.05),ω-3脂肪乳剂组术后24h、第6d上述指标与生理盐水组、中长链脂肪乳组相比无明显差别。表明大鼠腹部手术创伤后,经胃造口给予ω-3脂肪乳剂较生理盐水以及中长链脂肪乳剂干预,能明显下调术后72h血清炎症因子、Cox-2水平,有助于减轻全身炎症反应。3.ω-3脂肪乳剂组及中长链脂肪乳组:在大鼠腹部手术创伤后72h,血清胃泌素、胃动素水平均明显高于生理盐水组(P＜0.01),术后24h、第6d上述指标与术前相比无明显差别。但ω-3脂肪乳剂组与中长链脂肪乳剂组相比,术后24h、72h、6d血清胃泌素、胃动素水平无明显差别。表明腹部手术后经胃造瘘管给予两种脂肪乳剂均可在术后72h提高血清胃泌素、胃动素水平。说明脂肪乳剂均有通过抑制胃酸分泌、促进血清胃泌素分泌,直接刺激胃动素释放的作用。结论:大鼠腹部手术创伤后,经胃造口给予ω-3脂肪乳剂,较生理盐水、中长链脂肪乳剂能够明显下调手术创伤后72h血清炎症介质(IL-1、IL-6、TNF-α等)及COX-2水平,减轻全身炎症反应,从而减轻胃肠动力的抑制程度,改善胃排空率及小肠推进率,促进胃肠动力的恢复。ω-3脂肪乳剂组与中长链脂肪乳剂组均可在术后72h提高血清胃泌素、胃动素水平,但ω-3脂肪乳剂组较中长链脂肪乳剂组具有更明显的抗炎、促进胃肠动力恢复的作用,其作用机制与下调手术创伤后血清炎症介质、COX-2水平密切相关。更多还原

【Abstract】 PART I The Establishment of Rat Gastrointestinal Motility Dysfunction Model After Abdominal Operation And Its MechanismBackground: Early postoperative gastrointestinal motility dysfunction is a usual complication after laparotomy, especially after gastrointestinal operation. It can result in small bowel obstruction, serious infection and a second operation. It also can prolong hospital stay, increase hospital expenditure. At present, most of the researches were focused on the increase of inflammatory facts and the regulation of neuroendocrine system after operation, and our early studies showed that glucocorticoid could decrease blood inflammatory facts and increase the recovery of gastrointestinal motility after abdominal operation. But because of its side effects, glucocorticoid were limited in clinical treatment. So we established the rat gastrointestinal motility dysfunction model for further research.Aim: To establish the rat gastrointestinal motility dysfunction model after abdominal operation and study the mechanism.Method: The abdomina operation mode was established by gastrostomy and partial caecectomy in rat. By measuring inflammatory facts and gastrointestinal hormones, we investigated the machanism of gastrointestinal motility disorders after abdominal operation.24 wistar rats were randomly divided into normal group (n=6), operation group (n=18). Each group was divided into POD 1 group (n=6), POD 3 group (n=6) and POD 6 (n=6) according to the time of sacrifice.On POD 1, POD 3 and POD 6, the rat was sacrificed and gastric emptying rate, small bowel propulsion rate, serum gastrin(GAS), motilin(MTL), IL-1, IL-6, TNF-α, Cox-2 were measured.Results: 1. After partial caecectomy and gastrostomosis of rats, the gastric emptying rate and small bowel propulsion rate were reduced significantly on POD 1 and POD 3 (P<0.01), comparing to the normal group. But on POD 6 there was no difference.2.After partial caecectomy and gastrostomosis of rats, the serum GAS and MTL level were reduced significantly on POD 1 (P<0.01), comparing to the normal group. But on POD 3 and POD 6 there was no difference.3. After partial caecectomy and gastrostomosis of rats, the serum IL-1, IL-6, TNF-αand Cox-2 level were increased significantly on POD 1 and POD3 (P<0.01), comparing to the normal group. But on POD 6 there was no difference.Conclusion: After partial caecectomy in rats, the gastrointestinal mobility was inhibited greatly on POD 1, but on POD 6, the inhibition was disappeared and the gastrointestinal mobility was recovered to normal level. The inhibition was related to the decline of serum MTL level and the elevation of serum IL-1 and Cox-2 level. Serum GAS level decreased on POD 1 and gradually recovered from POD 3 to POD 6. PART II The Effect ofω-3 Fatty Acid on Rat Gastrointestinal Motility After Abdominal OperationBackground: Early postoperative gastrointestinal motility dysfunction is a usual complication after laparotomy, especially after gastrointestinal operation. It can result in small bowel obstruction, serious infection and a second operation. It also can prolong hospital stay, increase hospital expenditure. At present, most of the researches were focused on the increase of inflammatory facts and the regulation of neuroendocrine system after operation, and our early studies showed that glucocorticoid could decrease blood inflammatory facts and increase the recovery of gastrointestinal motility after abdominal operation. But because of its side effects, glucocorticoid were limited in clinical treatment.Because the patients who underwent abdominal operation usually could not take food for a while, enteral nutrion and parenteral nutrition become the necessary nutritional supports.ω-3 fatty acid have already been used in parenteral nutrition. Because of its advantages, including alleviating inflammation, inhibiting the growth of tumor, reducing blood-fat, etc,ω-3 fatty acid becomes a hotspot in domestic and overseas research. But there is no report about its relationship with gastrointestinal mobility after laparotomy.Aim: To study the relationship ofω-3 fatty acid with gastrointestinal mobility after laparotomy and its mechanism of action.Method: By infusing normal saline, intralipid andω-3 fatty acid through gastric tube, we studied the effect of normal saline, intralipid andω-3 fatty acid on rat gastrointestinal motility by investigating the inflammatory facts, the gastrointestinal hormones and the gastrointestinal motility.54 wistar rats were randomly divided into normal saline group (n=18), intralipid group (n=18) andω-3 fatty acid group (n=18). Each group was divided into POD 1 group (n=6), POD 3 group (n=6) and POD 6 (n=6) according to the time of sacrifice.Each day after partial caecectomy and gastrostomosis, the rats were perfused normal saline (12.5ml/d), intralipid (12.5ml/d, 5g/kg·d) andω-3 fatty acid (12.5ml/d, 5g/kg·d) through stomach-tube. On POD 1, POD 3 and POD 6, the rat was sacrificed according to its group, and gastric emptying rate, small bowel propulsion rate, serum gastrin(GAS), motilin(MTL), IL-1, IL-6, TNF-α, Cox-2 were measured.Results:1. On POD 3, the gastric emptying rate and small bowel propulsion rate inω-3 fatty acid group were higher than those in normal saline group and intralipid group, P<0.01, but on POD 1 and POD 6, there was no difference.2. On POD 3, the serum GAS and MTL level inω-3 fatty acid group were higher than those in normal saline group, P<0.01, but there was no difference betweenω-3 fatty acid group and intralipid group. On POD 1 and POD 6, there was no difference between them. This indicates the mechanism thatω-3 fatty acid promotes the recovery of gastrointestinal motility does not lie in the increase of serum GAS and MTL level. The possible reasons are: 1. Different food has different effect on gastrointestinal hormones. Bothω-3 fatty acid and intralipid belong to fatty acid, their effects to stimulating gastrointestinal hormones are similar, but more powerful than normal saline. 2.ω-3 fatty acid and intralipid inhibit the secretion of gastric acid, reduce PH value in stomach, then stimulate the secretion of GAS. 3.ω-3 fatty acid and intralipid can stimulate the secretion of MTL.3. On POD 3, the serum IL-1、IL-6、TNF-α、Cox-2 level inω-3 fatty acid group were lower than those in normal saline group and intralipid group, P<0.05. But on POD 1 and POD 6, there was no difference between them. This indicates thatω-3 fatty acid can decrease serum inflammatory facts level such as IL-1, IL-6, TNF-αand Cox-2 level. Because postoperative inflammation inhibits gastrointestinal mobility significantly,ω-3 fatty acid can accelerate the recovery of gastrointestinal mobility after operation.Conclusion:ω-3 fatty acid can accelerate the recovery of gastrointestinal mobility after caecectomy in rats. Its mechanism of action could be: co-3 fatty acid can decease serum inflammatory facts such as IL-1, IL-6, TNF-αand Cox-2 level, relieve postoperative inflammation.ω-3 fatty acid and intralipid can increase serum GAS, MTL level on POD 3, but comparing to intralipid,ω-3 fatty acid can accelerate the recovery of gastrointestinal mobility and inhibit inflammation after abdominal operation.更多还原