急性束缚应激对大鼠结肠敏感性的影响

背景:内脏高敏感性是肠易激综合征(IBS)重要的病理生理特征,而应激事件能诱发或加重IBS患者的症状。目的:了解急性束缚应激对大鼠结肠敏感性的影响和持续时间,以及对单个平滑肌细胞收缩活动的影响。方法:建立急性部分束缚应激大鼠动物模型,于0天(应激前1天)、1天(应激当天)、2天(应激后1天)行结直肠气囊扩张．并行腹壁回撤反射(AWR)评分;分离平滑肌细胞,测定结肠平滑肌细胞的收缩百分率。结果:20 mm Hg和40 mm Hg扩张压力下,束缚组1天的AWR评分显著高于对照组(1．68±0．79对0．81±0．42、2．45±0．72对1．58±0．60,P<0．05);束缚组大鼠1天时AWR评分在20 mm Hg(P1=0．001;P3=0．006)和40 mm Hg(P2=0．012,P4=0．033)扩张压力下与0天、 2天相比显著增加,但在60 mm Hg和80 mm Hg扩张压力下以及对照组在每天的评分均无显著差异;束缚组结肠平滑肌细胞的收缩百分率与对照组无显著差异(P=0．523)。结论:急性束缚应激使大鼠结肠对低压力球囊扩张的敏感性呈一过性增加,对大鼠单个平滑肌细胞的收缩活动没有影响。

肠易激综合征内脏敏感性检测与评价方法的研究进展

肠易激综合征(IBS)是临床上常见的功能性胃肠病,内脏敏感性增加是IBS重要的病理生理特征之一,对内脏敏感性的检测和评价对IBS临床诊断及治疗具有实际意义。本文通过检索、整理关于IBS内脏敏感性的研究,从中枢与外周两个角度出发,综述了对IBS患者和模型动物内脏敏感性增加状态的检测及评估方法,发现目前研究存在方法较单一、运用受限等问题。在未来的研究中,可以进一步探索各种评价方法在动物实验与人体试验中运用的可能性。

Enhanced Chemotherapy Sensitivity of Human Colon Cancer Cells to 5-Fluorouracil by siRNA Recombinant Expression Vector Targeting Survivin Gene

Objective To investigate the effects of small interfering RNA （siRNA） recombinant expression vector targeting survivin gene on chemotherapy sensitivity of human colon cancer cells to 5-fluorouracil. Methods siRNA recombinant expression vector targeting survivin gene was constructed and transfected into human colon cancer cell lines LOVO. After 48 hours of transfection, cells were harvested for analysis of survivin mRNA and protein expressions using RT-PCR and Western blot. In addition, after human colon cancer cell lines were treated with Survivin siRNA and/or 5-fluorouracil, MTT assay and flow cytometry were used to analyze cell proliferation and apoptosis. Results Restriction endonuclease analysis confirmed that siRNA recombinant expression vector targeting survivin gene was successfully constructed. Inhibitory ratios of survivin mRNA and protein expressions by Survivin siRNA were 36.33% and 44.65%, respectively. Survivin siRNA combined with 5-fluorouracil significantly increased the cell proliferation inhibitory ratio and apoptosis ratio compared with 5-fluorouracil treatin~ alone （P〈0.05）. Conclusion The siRNA recombinant expression vector targeting survivin gene can inhibit the expression of survivin gene, and enhance chemotherapy sensitivity of human colon cancer cells to 5- fluorouracil.

Study of sensitivity of different chemotherapeutic agents on colon cancer cell line SW480

Objective:The aim of this study was to investigate the sensitivity of chemotherapeutic agents 5-FU,cisplatin(DDP) or TAXOL on colon cancer cell line SW480 with different methods,to find out the best examine time period for further study of chemotherapeutic sensitivities.Methods:The SW480 cell was treated with 5-FU(200μg/mL),DDP(150μg/mL) or TAXOL(50μg/mL) respectively for 4h,8h or 12h.MTT assay was used to examine the cell survival rate,Annexin V/PI assay was used to analysis the apoptosis rate,Western Blot assay was applied to examine the expression of apoptotic protein.Results:(1) Results of MTT assay showed that the survival rate of SW480 cells at 4h,8h or 12h was:5-FU(200μg/mL)96.0%±8.2%,85.4%±7.8%,74.4% ±10.2%(P<0.05);DDP(150μg/mL) 99.0%±6.4%,88.7%±4.7%(P<0.05),46.9%±2.6%(P<0.01);TAXOL(50μg/mL) 51.5%±4.2%(P<0.01),31.9%±3.1%,17.6%±2.3%,or blank group 97.2%±5.8%,98.7%±7.2%,97.5%±7.5% respectively.(2) The apoptosis rate of cancer cells at 4h,8h or 12h was:control group:3.4%±0.2%,6.2%±0.4%,7.0%±0.5%;5-FU(200μg/mL) 4.0%±0.3%,4.8%±0.4%,7.7%±0.7%;DDP(150μg/mL) 8.5%±0.9%,18.6%±1.6%(P<0.05),67.0%±6.2%(P<0.01);or TAXOL(50μg/mL) 32.0%±5.2%(P<0.01),76.6%±8.5%,94.0% ±8.2%,respectively.(3) Western Blot assay showed that the expression of apoptosis associated protein.PARP,X-linked inhibitor of apoptasis(XIAP),Caspase-9 and Bcl-xL were changed.Conclusion:The sensitivity of chemotherapy could be assessed by MTT assay,Annexin V/PI assay and Western Blot.The best examine time of the three chemotherapuc agents was 5-FU(200μg/mL):>12h,DDP(150μg/mL):8-12h,or TAXOL(50μg/mL):<4h.