全层铺片技术显示胃肠道不同部位Cajal间质细胞

正Cajal间质细胞(interstitial cells of Cajal,ICC),是西班牙神经解剖学家Santiago Ramony Cajal于1893年首次在胃肠道中发现的一类特殊间质细胞,与胃肠道平滑肌和神经纤维末梢在解剖学上有紧密联系,具有独立功能,既是胃肠起搏细胞,又具有传导神经递质的作用~[1]。ICC广泛存在于哺乳动物的整个消化道管壁内,按分布区域可大致分为:分布于胃、小肠和结肠内的环肌与纵行肌之间的肌间神经丛ICC;位于黏膜下环肌层表面的ICC;位于小肠深肌丛区域的ICC;广泛散布于环肌和纵肌肌束内的ICC~[2]。目前消化道全层铺片技术由于能够直观、全面地显示ICC的分布、形态以及形成的细胞网络,而成为研究胃肠神经系统的重要方法之一,但文献中却鲜少提及此方法的详细操作过程。已知ICC特异性表达由原癌基因c-kit编码的受体酪氨酸激酶     

Role of reactive oxygen species in triptolide-induced apoptosis of renal tubular cells and renal injury in rats

This study investigated the role of reactive oxygen species(ROS) in the pathogenesis of triptolide-induced renal injury in vivo.Rats were randomly divided into 4 groups(n=5 in each):triptolide group in which the rats were intraperitoneally injected with triptolide solution at a dose of 1 mg/kg of body weight on day 8;control group in which the rats received a single intraperitoneal injection of 0.9% physiological saline on day 8;vitamin C group in which the rats were pretreated with vitamin C by gavage at a dose of 250 mg/kg of body weight per day for 7 days before the same treatment as the control group on day 8;triptolide+vitamin C group in which the rats were first subjected to an oral administration of vitamin C at a dose of 250 mg/kg of body weight per day for 7 days,and then to the same treatment as the triptolide group on day 8.All the rats were sacrificed on day 10.Blood samples were collected for detection of plasma creatinine(Pcr) and plasma urea nitrogen(PUN) concentrations.Both kidneys were removed.The histological changes were measured by haematoxylin-eosin(HE) staining.The production of ROS was determined by detecting the fluorescent intensity of the oxida-tion-sensitive probe rhodamine 123 in renal tissue.Renal malondialdehyde(MDA) content was meas-ured to evaluate lipid peroxidation level in renal tissue.TUNEL staining was performed to assess apop-tosis of renal tubular cells.Renal expression of apoptosis-related proteins Bcl-2,Bax,Bid,Bad,Fas and FasL,as well as corresponding encoding genes were assessed by Western Blotting and real-time PCR.The results showed that triptolide treatment promoted the generation of a great amount of ROS,up-regulated the expression of Bax,Bid,Bad,Fas and FasL at both protein and mRNA levels,as well as the ratio of Bax to Bcl-2,and caused the apoptosis of renal tubular cells and renal injury.However,pretreatment with an antioxidant,vitamin C,significantly reduced the generation of ROS and effectively inhibited the triptolide-induced apoptosis of renal tubular cells and renal injury.It was concluded that ROS plays a critical role in triptolide-induced apoptosis of renal tubular cells and renal injury.The protective administration of vitamin C may help alleviate triptolide-induced renal injury and nephrotoxicity.     

雷公藤甲素诱发大鼠急性肾损伤的机制

目的:观察雷公藤甲素对大鼠肾脏的急性毒性作用,并探讨其发生机制.方法:将雄性SD大鼠随机分为1个对照组和2个实验组,对2个实验组大鼠给予腹腔注射剂量分别为1,2 mg· kg-1的雷公藤甲素,对照组大鼠则给予相当量的空白对照液.注射后48 h将所有大鼠处死,采集心脏血液并取出双侧肾脏,检测血清尿素氮(BUN)与肌酐(Cr)含量,观察HE染色切片上肾组织形态学改变情况;应用原位末端标记法(TUNEL)检测肾组织细胞凋亡情况;测定肾组织内SOD,GSH-Px活性以及MDA含量.结果:一次性大剂量注射雷公藤甲素可在短时间内对大鼠肾脏造成严重损伤,剂量越大越显著;经雷公藤甲素处理后,肾组织中SOD与GSH-Px活性明显降低,而MDA含量则明显升高,且均与肾脏的损伤程度密切相关.结论:肾脏是雷公藤甲素急性毒性作用重要的靶器官,氧化应激在雷公藤甲素对肾脏造成的毒性损害中发挥了重要作用.