烫伤大鼠结肠动力基本功能单位细胞损害和内质网应激研究  

Study on endoplasmic reticulum stress and injury to basic function unit of colonic motility in rats with scald injury

作　　者：李颖[1] 郭力[1] 

机构地区：[1]四川泸州医学院附属医院整形烧伤科,646000

出　　处：《中华烧伤杂志》2009年第3期193-196,共4页Chinese Journal of Burns

基　　金：四川省科学技术厅重点科技自筹项目（05JY029-143）;四川省教育厅自然科学科研项目（2003C011）

摘　　要：目的了解严重烫伤大鼠结肠壁内神经运动末梢-肌间丛cajal间质细胞（ICC）-平滑肌细胞超微结构改变以及葡萄糖调节蛋白78（GRP78）、半胱氨酸天冬氨酸蛋白酶12（caspase-12）表达情况，探讨其在烫伤大鼠结肠动力损伤中的可能机制。方法采用简单随机法将50只SD大鼠分为烫伤组（40只）：大鼠造成30％TBSAⅢ度烫伤，伤后腹腔注射乳酸林格液（50mg／kg）复苏。于伤后3、6、12、24h处死大鼠，在距盲肠约5cm处剪取近端结肠4cm肠管，取中间各1cm分别用体积分数3％戊二醛及体积分数10％甲醛固定。对照组（10只）除不烫伤外，其余处理同烫伤组。取戊二醛固定的标本，透射电镜下观察大鼠肠道细胞变化情况。取甲醛固定的标本，采用免疫组织化学法检测结肠壁中GRP78和caspase-12的表达。结果透射电镜下，对照组大鼠结肠平滑肌细胞排列整齐，肌细胞内细胞器丰富，核居中，常染色质均匀，线粒体嵴较多、滑面内质网较少，肌间丛神经元细胞器丰富，紧邻肌间丛神经元可见ICC；烫伤组肠道平滑肌细胞形状不规则，排列紊乱，核周隙增宽，细胞内有溶解性大空泡，线粒体空泡样变，嵴溶解、固缩，粗面内质网扩张并部分溶解，ICC核周细胞质明显减少。烫伤组伤后3、6、12h GRP78评分分别为（4．3±0．9）、（6．0±0．7）、（4．8±1．1）分，均高于对照组[（2．4±0．7）分，P〈0．05]；烫伤组伤后6～24h caspase-12评分均高于对照组（P〈0．05）。对照组细胞均有GRP78表达，烫伤组强度染色主要出现在黏膜和肌间神经丛、间质细胞，而平滑肌细胞多呈轻中度染色。烫伤后3、12hGRP78呈阳性表达，伤后6h呈强阳性。caspase-12在伤后3h阳性表达不明显，伤后6、24h表达呈弱阳性，伤后12h表达呈阳性；对照组未见caspase-12表达。结论严重烫伤后大鼠结肠壁内神经运动末梢-肌间�Objective To observe expressions of glucose-regulated protein （GRP78） and caspase- 12 in nervous system-interstitial cells of Cajal （ICC） in smooth muscle in colonic wall in rats with scald injury, as well as their relevant uhrastructural changes, so as to probe the possible mechanisms of dynamic damage in murine colon after a scald injury. Methods Fifty healthy Sprague-Dawley rats were randomly divided into scald （n =40） and control （n = 10） groups. Rats in scald group were inflicted with 30% TBSA full-thickness scald, and received an intraperitoneally injection of Ringer lactate solution （50 mg/kg） for resuscitation, while those in control group had similar treatment with the exception of scald. Rats in control group and scald group were sacrificed at 3, 6, 12, 24 post scald hour （PSH, 10 rats at each time point） for collection of 4 cm of colonic tissue, 5 cm proximal to the cecum. A segment of colonic wall, 1 cm in length, was obtained from the middle of the harvested segment of colon, and it was fixed with 3% glutaraldehyde or 10% formaldehyde. The samples fixed with glutaraldehyde were used to observe ultrastructural alterations under transmission electron microscope, while that with formaldehyde were used to observe expressions of GRP78 and caspase-12 in colonic wall by immunohistochemical assay. Results The colonic smooth muscle cells of rats in control group showed regular arrangment, their organelles were abundant, nucleus centrally located, euchromatin distributed evenly with more abundant mitochondrial cristae and less smooth endo-plasmic reticulum, neuronal organelles were abundant in intermuscular plexus, and ICC could be seen in the neighborhood of neurons. The colonic smooth muscle ceils appeared in irregular and disordered manner in scald group, perinuclear space was widened, intercellular vacuoles were observed, mitochondria showed vacuolation degeneration with dissolved and condensed cristae, rough endoplasmic reticula were dilated with partial dissolution, and perinuclea

关 键 词：烧伤 结肠 细胞凋亡 半胱氨酸天冬氨酸蛋白酶12 葡萄糖调节蛋白78 

分 类 号：R285.5[医药卫生—中药学]