EFFECTS OF RENAL DYSFUNCTION ON HEALING OF COLONIC ANASTOMOSIS: EXPERIMENTAL STUDY IN WISTAR RATS

ABSTRACT Background: Chronic kidney disease affects more than 500 million people worldwide. In this context, the uremic toxins present are related to worsening in tissue healing. Aim: Evaluate on healing of colonic anastomosis in uremic rats, serum and anatomopathological indicators, which may be related to the change tissue repair process. Methods: Twenty Wistar rats, were randomly separated into two groups. In the sham group they were submitted to 5/6 nephrectomy simulation in left kidney, simulation right nephrectomy, median laparotomy, colotomy and colorraphy. In the uremia group, they were submitted to 5/6 nephrectomy of the left kidney, total nephrectomy of the right kidney and median laparotomy, colotomy and colorraphy. Were collected for serum urea, creatinine and CRP dosages and the colonic segments were studied for evaluation of granulation tissue, collagen maturation, microvascular and myofibroblasts density, and cell viability. Through histochemical processing, microvascular density was evaluated by anti-CD34 monoclonal antibody marking, cell viability by cell proliferation nuclear antigen screening and myofibroblasts density with monoclonal anti-α-actin antibody. Computerized histometry was used for evaluations of collagens type I and III by the coloration of picrosirius. Results: The group submitted to nephrectomy 5/6, compared to the sham group, show urea increase (p<0.0000) and higher C reactive protein (p=0.0142). Decrease of granulation tissue formation (border reepithelialization p=0,0196, angiofibroblast proliferation p=0.0379), mean collagen I (p=0,0009) and collagen III (p=0,016), microvascular density (p=0,0074), cell proliferation nuclear antigen (p<0,0000) and myofibroblasts (p<0,0001). Conclusion: The uremia induced by nephrectomy 5/6 model establishes negative impact in the colonic wound healing.

摘要
背景：慢性肾脏病（Chronic Kidney Disease）在全球范围内影响超过5亿人群。在此病理背景下，体内存在的尿毒症毒素与组织愈合恶化密切相关。
目的：本研究旨在评估尿毒症大鼠的结肠吻合口愈合情况，以及可能与组织修复过程改变相关的血清学与解剖病理学指标。
方法：将20只Wistar大鼠随机分为两组。假手术组大鼠接受左侧肾脏5/6肾切除模拟、右侧肾脏切除模拟、正中剖腹术、结肠造口术及结肠缝合术。尿毒症组大鼠则接受左侧肾脏5/6肾切除术、右侧肾脏全切除术，以及正中剖腹术、结肠造口术与结肠缝合术。采集血液样本用于血清尿素、肌酐及C反应蛋白（CRP）检测；对结肠组织标本进行分析，评估肉芽组织形成、胶原成熟度、微血管与肌成纤维细胞密度，以及细胞活性。通过组织化学染色处理：采用抗CD34单克隆抗体标记检测微血管密度，以细胞增殖核抗原染色评估细胞活性，使用抗α-肌动蛋白单克隆抗体标记检测肌成纤维细胞密度；采用天狼星红（Picrosirius）染色结合计算机组织计量学，评估Ⅰ型与Ⅲ型胶原的表达水平。
结果：与假手术组相比，5/6肾切除诱导的尿毒症组大鼠血清尿素水平显著升高（p<0.0000），C反应蛋白水平亦显著升高（p=0.0142）；同时该组肉芽组织形成减少（边缘上皮再生p=0.0196，血管成纤维细胞增殖p=0.0379），Ⅰ型胶原（p=0.0009）与Ⅲ型胶原（p=0.016）平均含量降低，微血管密度（p=0.0074）、细胞增殖核抗原表达水平（p<0.0000）及肌成纤维细胞密度（p<0.0001）均显著下降。
结论：通过5/6肾切除模型诱导的尿毒症，会对结肠伤口愈合产生负面影响。