雌激素对视网膜新生血管生成作用的研究

目的探讨用去势和假去势方法研究雌激素在眼部疾病作用的可行性,以及雌激素对视网膜新生血管生成的影响。方法22只健康成熟雌性SD大鼠随机分为2组,分别用去势和假去势方法建立2组体内雌激素水平有明显差异的雌性SD大鼠模型,用阴道上皮涂片方法证实;用光动力诱导方法建立视网膜静脉阻塞模型,雌激素影响视网膜新生血管的生成情况用荧光素眼底血管造影(FFA)证实。结果去势和假去势手术操作简单,去势SD大鼠手术后成熟值降低明显,而假去势组SD大鼠手术前后成熟值变化不明显(P=0.000,P=0.756),FFA显示去势组SD大鼠荧光素渗漏呈大片状,明显强于假去势组的弥漫点状或小片状(P=0.023)。结论去势和假去势方法是研究雌激素在眼部疾病作用的可靠方法,雌激素对视网膜新生血管生成有明显作用,雌激素水平降低时视网膜新生血管生成增加。

Reversal of hyperglycemia in diabetic rats by portal vein transplantation of islet-like cells generated from bone marrow mesenchymal stem cells

AIM: To study the capacity of bone marrow mesenchymal stem cells (BM-MSCs) trans-differentiating into islet-like cells and to observe the effect of portal vein transplantation of islet-like cells in the treatment of streptozotocin-induced diabetic rat. METHODS: BM-MSCs were isolated from SD rats and induced to differentiate into islet-like cells under defined conditions. Differentiation was evaluated with electron microscopy, RT-PCR, immunofluorescence and flow cytometry. insulin release after glucose challenge was tested with ELiSA. Then allogeneic islet-like cells were transplanted into diabetic rats via portal vein. Blood glucose levels were monitored and islet hormones were detected in the liver and pancreas of the recipient by immunohistochemistry. RESULTS: BM-MSCs were spheroid adherent monolayers with high CD90, CD29 and very low CD45 expression. Typical islet-like cells clusters were formed after induction. Electron microscopy revealed that secretory granules were densely packed within the cytoplasm of the differentiated cells. The spheroid cells expressed islet related genes and hormones. The insulin-positive cells accounted for 19.8% and mean fluorescence intensity increased by 2.6 fold after induction. The cells secreted a small amount of insulin that was increased 1.5 fold after glucose challenge. After transplantation, islet-like cells could locate in the liver expressing islet hormones and lower the glucose levels of diabetic rats during d 6 to d 20.CONCLUSION: Rat BM-MSCs could be transdifferentiated into islet-like cells in vitro . Portal vein transplantation of islet-like cells could alleviate the hyperglycemia of diabetic rats.

The pain-related behavior changes correlate with the bone damage in a rat model of rheumatoid arthritis

In view of the extensive bone damage in rheumatoid arthritis, we used a commonly utilized animal model to detect behavioral changes in pain-related and the bone damage during the early disease, and to explore the correlation between bone damage and pain-related behavioral changes. Methods： Arthritis were induced in Sprague-Dawley （SD） male rats by injecting complete Freund＇s adjuvant （CFA） into the tails. Pain-related behavior changes were studied using the Hargreaves, VonFrey, and acetone tests on the 0, 7, 14, day and 28 day after CFA injection. The rats were sacrificed according the same schedule. The bone damage of the right proximal tibia was studied by microCT scan and bone histological slices. Results： Animals developed soft tissue inflammation and polyarthritis on 7 days after CFA injection, and arthritic score proved obvious arthritis were established within the study period. Mechanical hyperalgesia and cold allodynia were present in the affected hind paw from the 7 day through the 28 day, but the heat hyperalgesia and the mechanical allodynia lasted a short time after CFA injection. Trabecular bone number （Tb.N）, Tissue Mineral Content （TMC） and Bone Volume to Tissue Volume （BV/TV） in the proximal tibia by microCT scan were also reduced after induction, especial 14 days after CFA injection. The bone histologicalslices showed the trabecular bone and proteoglycan diminished, the bone damage severity scores became more severely on the 7 day after CFA injection. Using analysis of covariance, these changes had statistical significance compared with baseline. By linear regression analysis demonstrated mechanical hyperalgesia and cold allodynia correlated well with arthritic score, bone damage parameters and bone damage severity scores. Conclusion： Adjuvant-induced arthritis （AA） were observed after CFA injection and lasted within the later experimental period. Pain-related behavioral changes were observed in the early time of AA. Bone damage was also occurred with arthritis development. Pain-related behavioral change correlated well with arthritic score and bone damage parameters

Preventive and therapeutic effects of NF-kappaB inhibitor curcumin in rats colitis induced by trinitrobenzene sulfonic: acid

AIM: To ascertain the molecule mechanism of nuclear factor-KB (NF-κB) inhibitor curcumin preventive and therapeutic effects in rats' colitis induced by trinitrobenzene sulfonic acid (TNBS). METHODS: Sixty rats with TNBS-induced colitis were treated with 2.0% curcumin in the diet. Thirty positive control rats were treated with 0.5% sulfasalazine (SASP). Thirty negative control rats and thirty model rats were treated with general diet. Changes of body weight together with histological scores were evaluated. Survival rates were also evaluated. Cell nuclear NF-κB activity in colonic mucosa was evaluated by using electrophoretic mobility shift assay. Cytoplasmic IκB protein in colonic mucosa was detected by using Western Blot analysis. Cytokine messenger expression in colonic tissue was assessed by using semiquantitative reverse-transcription polymerase chain reaction. RESULTS: Treatment with curcumin could prevent and treat both wasting and histopathologic signs of rats with TNBS-induced intestinal inflammation. In accordance with these findings, NF-κB activation in colonic mucosa was suppressed in the curcumin-treated groups. Degradations of cytoplasmic IκB protein in colonic mucosa were blocked by curcumin treatment. Proinflammatory cytokine messenger RNA expression in colonic mucosa was also suppressed. CONCLUSION: This study shows that NF-κB inhibitor curcumin could prevent and improve experimental colitis in murine model with inflammatory bowel disease (IBD). The findings suggest that NF-κB inhibitor curcumin could be a potential target for the patients with IBD.

Induction of experimental acute ulcerative colitis in rats by administration of dextran sulfate sodium at low concentration followed by intracolonic administration of 30% ethanol

Several models of experimental ulcerative colitis have been reported previously. However, none of these models showed the optimum characteristics. Although dextran sulfate sodium-induced colitis results in inflammation resembling ulcera-tive colitis, an obvious obstacle is that dextran sulfate sodium is very expensive. The aim of this study was to develop an inex-pensive model of colitis in rats. Sprague-Dawley rats were treated with 2% dextran sulfate sodium in drinking water for 3 d fol-lowed by an intracolonic administration of 30% ethanol. The administration of 2% dextran sulfate sodium followed by 30% ethanol induced significant weight loss, diarrhea and hematochezia in rats. Severe ulceration and inflammation of the distal part of rat colon were developed rapidly. Histological examination showed increased infiltration of polymorphonuclear leukocytes, lymphocytes and existence of cryptic abscesses and dysplasia. The model induced by dextran sulfate sodium at lower concentra-tion followed by 30% ethanol is characterized by a clinical course, localization of the lesions and histopathological features similar to human ulcerative colitis and fulfills the criteria set out at the beginning of this study.

Gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine in rat with ulcers and expressions of ras and c-erbB2 genes

Objective: To observe the series of pathological changes during the development of gastric adenocarcinoma in ulcerative rats induced by N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), and the expression profile of related oncogenic protein.Methods: MNNG was administered in rats with ulcers due to acetic acid treatment to induce gastric cancer, and the protein expressions of ras and c-erbB2 genes in the ulcer were examined immunohistochemically along with pathological examination.Results: The incidence of gastric adenocarcinoma in the model group reaches 40% (6/15), while none of the rats developed cancer in the control group with ulcers.Positive expressions of the proteins of p21ras and c-erbB2 were observed in the tissues undergoing canceration in the 6 rats of model group, but were not observed in the 5 control rats; p53 protein expression, however, failed to be detected in both groups.Conclusion: A new animal model of gastric cancer has been established in rats with gastric ulcer after MNNG treatment, which may facilitate the pharmacological research of gastric cancer.

Modifi cation of sleep architecture in an animal model of experimental cirrhosis

AIM： To analyze the polygraphic sleep patterns during cirrhosis progression in a rat model by repeated CCh administration. METHODS： Male Wistar rats received three weekly injections of CCl4 for 11 wk, and were analyzed before and during the induction of cirrhosis. Rats were im- planted with electrodes to record their sleep patterns. Polygraph recordings were made weekly over 11 wk for 8 h, during the light period. After a basal recording, rats received three weekly injections of CCl4. Histological confirmation of cirrhosis was performed after 11 wk. RESULTS： The results showed a progressive decrease in total wake time that reached statistical significance from the second week of treatment. In addition, there was an increase in total time of slow wave sleep （SWS）Ⅱ and rapid eye movement sleep （REM sleep） in most of the 11 wk. SWS I showed no significant variations. During the final weeks, a significant increase in REM sleep frequency was also observed. Histological analyses of the livers showed unequivocal signs of cirrhosis. CONCLUSION： These data suggest that hepatic failure produced by CCh administration is capable of modifying the sleep pattern even after only a few doses.

半夏白术天麻汤化裁方治疗高脂血症的研究

目的:实验观察半夏白术天麻汤化裁方对高血脂模型大鼠相关指标的影响,为临床用药提供药效学依据。方法:给予大鼠高脂饲料4周,造成高血脂大鼠模型,同时给予受试药半夏白术天麻汤化裁方,测定给药过程中大鼠体重变化及给药后高脂模型大鼠甘油三酯(TG)、胆固醇(CHOL)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、载脂蛋白A1(apoA1)、载脂蛋白B(apoB),超氧化物歧化酶(SOD),丙二醛(MDA)的变化。结果:半夏白术天麻汤化裁方3个剂量组体重与模型组比较,高剂量组体重较同期模型对照组比较有所增加。半夏白术天麻汤化裁方3个剂量组对血清甘油三酯均具有显著地降低作用,高剂量组对血清CHOL,LDL水平亦具有显著地降低作用,与模型组比较具有显著性差异(P<0.05)。半夏白术天麻汤化裁方3个剂量组能不同程度提高血清HDL水平,但与模型组比较无显著性差异。各组大鼠血清apo A1水平均无显著性差异,各剂量组和血脂康对照组不同程度降低apo B水平,其中半夏白术天麻汤化裁方高剂量组最为明显。半夏白术天麻汤化裁方3个剂量组不同程度提高SOD活性,降低MDA含量,其中以高剂量作用最为明显。结论:半夏白术天麻汤化裁方具有明确的改善高血脂相关指标的作用。