翻白草对实验性糖尿病大鼠治疗作用的研究

目的:观察翻白草对实验性糖尿病大鼠治疗作用.方法:给动物灌胃给药,用四氧嘧啶制备实验性糖尿病大鼠模型.应用免疫组织化学方法观察胰岛B细胞形态学改变,比色分析法检测血糖、胆固醇及甘油三酯的含量.结果:翻白草对四氧嘧啶性糖尿病大鼠的胰岛B细胞有明显的修复作用并可以降低血糖、胆固醇及甘油三酯的含量.结论:翻白草对实验性糖尿病大鼠具有治疗作用.     

糖脂平对实验性2型糖尿病大鼠糖、脂及胰岛素代谢的影响

目的 观察糖脂平对实验性2型糖尿病大鼠糖、脂及胰岛素代谢的影响。方法 SD大鼠在高热量饲料喂养1个月的基础上，以小剂量链脲佐菌素（33mg/kg）尾静脉注射建立实验性2型糖尿病模型鼠，同时随机分为模型组、糖脂平低剂量和高剂量组、格列剂特组。灌胃给药，每天一次，疗程36天。结果 糖脂平能明显降低模型鼠的体质量增长率，明显抑制模型鼠血清甘油三脂的升高。对模型鼠增高的空腹血糖有明显降低作用，且又能抑制糖负荷1h、3h后血糖的升高。对模型鼠呈现的高胰岛素和高胰高血糖素血症分别有下降趋势和明显降低作用。结论 糖脂平能减轻模型鼠的胰岛素抵抗，可能与抑制模型鼠的胰高血糖素分泌、体质量增长、改善糖脂代谢紊乱有关。     

蒲桃种子提取物对四氧嘧啶糖尿病鼠血糖的影响

目的：探讨蒲桃种子提取物对实验性糖尿病动物血糖的影响。方法：采用四氧嘧啶诱发实验性糖尿病动物模型，用葡萄糖氧化酶法测血糖，用放射免疫法测血清胰岛素。结果：蒲桃种子提取液能降低四氧嘧啶糖尿病小鼠、大鼠的血糖水平，有增加动物对葡萄糖耐量的作用。结论：蒲桃种子提取液对实验性糖尿病动物具有降糖作用。     

糖尿病鼠肺间质免疫组织化学的研究

目的 探讨糖尿病鼠肺间质免疫组织化学的研究。方法 建立实验性糖尿病模型后四周，采用特殊染色法，免疫组织化学法和MD20型彩色图像分析系统对特殊染色与免疫组化学染色都先进行图像测量，修正和分析，测定积分光密度和相对含量，并同对照组进行比较。结果 糖尿病早期肺间质弹性纤维和网状纤维增多，增粗，相对含量增高。结论 糖尿病早期肺间质病变主要表现为细胞外基质增加，其机制为高糖状态导致非酶糖化等作用增强。这是导致弥漫性肺间质纤维化的病理生理基础。     

实验性大鼠糖尿病高脂血症模型制作方法的改进

①目的探讨实验性大鼠2型糖尿病高脂血症动物模型方法的建立。②方法大鼠分4次腹腔注射四氧嘧碇，同时喂饲高脂饮食，于第1次给药后的48小时、1周、2周，6周分别测定空腹血糖及体重以及甘油三酯与胆固醇含量的变化。③结果成功诱导实验性大鼠2型糖尿病高脂血症动物模型。④结论连续多次给予四氧嘧碇，同时喂饲高脂饮食，能成功诱导2型糖尿病高脂血症动物模型，且成功率高，动物死亡率低。     

芦荟多糖对糖尿病大鼠血清肌酐和尿素水平的影响

目的 观察芦荟多糖山绿茶对大鼠糖尿病肾功能损害有无对抗作用.方法 取S D大鼠96只,将大鼠随机分成正常组、模型组、阳性药组、糖高、中、低3个剂量组等6个组,用链脲佐菌素致大鼠糖尿病模型.灌胃给药,阳性药组用二甲双胍、芦荟多糖剂量组用芦荟多糖山绿茶,给药1h后检测大鼠血清肌酐和尿素水平.结果 阳性药组血清肌酐水平降低、血清尿素水平无明显变化;芦荟多糖剂量组血清肌酐水平和血清尿素水平均显著降低.结论 芦荟多糖山绿茶有减轻实验性糖尿病大鼠肾脏损伤的作用.     

胸腺素对实验性精索静脉曲张鼠免疫功能的影响

通过部分结扎左肾静脉诱导实验性精索静脉曲张，研究了胸腺素对免疫功能的影响。结果显示，未用药组实验性精索静脉曲张鼠脾细胞中溶血空斑（PFC）的形成和白细胞介素-2的诱生能力均明显降低（P＜0.05、P＜O.01）；给予胸腺素4周后，PFC的形成明显升高（P＜O.O1）。提示，实验性精索静脉曲张鼠存在免疫机能紊乱。胸腺素能够促进免疫功能，维持免疫功能的稳定。胸腺-神经内分泌免疫网络在精静脉曲张不育的发病机制中起着十分重要的作用。     

梅连消渴胶囊联合二甲双胍对糖尿病大鼠胰岛细胞及血糖水平的影响

目的观察中药复方梅连消渴胶囊联合二甲双胍对实验性糖尿病大鼠血糖水平及胰岛细胞的保护作用。方法以高脂高
糖联合链脲佐菌素（STZ）复制大鼠Ⅱ型糖尿病模型,分别以低剂量二甲双胍和梅连消渴胶囊及二者联合用药灌胃给药4周,测
定实验性糖尿病大鼠血糖水平;以HE染色观察胰岛病理改变;以醛复红染色计算胰岛β细胞数量。结果大鼠分别给予低剂量
二甲双胍及梅连消渴胶囊2、4周后,空腹血糖水平及葡萄糖耐量无显著变化;二者联合给药2、4周后,大鼠血糖水平、糖化血红
蛋白水平显著降低,葡萄糖耐量显著改善。同时,胰岛β细胞数量增加,胰岛组织病理改变减轻。结论梅连消渴胶囊与二甲双
胍联合用药后,糖尿病大鼠血糖水平显著降低,对损伤的胰岛细胞有保护和修复作用。
     

岩藻多糖对2型糖尿病的预防作用

目的研究岩藻多糖对链脲佐菌素诱导实验性2型糖尿病大鼠的预防作用。方法建立2型糖尿病大鼠动物模型,预防给药岩藻多糖（600mg/kg、400mg/kg、200mg/kg）5周后,测定大鼠、空腹血糖、血脂和血清胰岛素水平。结果高脂高糖饮食联合腹腔注射小剂量链脲佐菌素（30 mg/kg）可诱导大鼠2型糖尿病模型。岩藻多糖可降低大鼠空腹血糖,提高基础胰岛素水平,升高胰岛素敏感指数,改善胰岛素抵抗。并能降低血清胆固醇、甘油三酯、低密度脂蛋白胆固醇含量,升高高密度脂蛋白胆固醇水平。结论岩藻多糖对实验性2型糖尿病的发生有预防作用。     

异体胰岛移植实验研究

对于糖尿病受体,胰岛移植以哪个部位最为合适和有效,各作者意见不一。免疫抑制剂在胰岛移植中的作用也尚有争论。本文通过腹腔内和肾包膜下的胰岛移植的实验研究,比较其疗效差别,并对免疫抑制剂的作用也作了初步观察。鉴于国内外实验性胰岛移植的胰岛分离较少采用组织培养的方法,而目前我国临床胰岛移植则多采用这一方法,因此,本实验所使用的胰岛分离方法为组织培养法,旨在使实验条件尽量接近我国的临床实际。     

The endothelial cells in islets of langerhans

The blood vessels of the pancreatic islets are of crucial importance for oxygen and metabolite supply, and dispersal of secreted hormones. In addition to this, endothelial cells have an important role in the revascularization process after islet transplantation. Studies have reported signs of poor engraftment of transplanted islets, presumably due to impaired revascularization. The aims of this study were to investigate islet endothelial cells and the revascularization process of transplanted islets. The lectin Bandeiraea simplicifolia was found to consistently stain endothelium of both endogenous and transplanted pancreatic islets. By using this marker, we investigated the vascular density of both endogenous and transplanted islets of C57BL/6 mice. One month post-transplantation, a time point when the implants are assumed to be completely revascularized, the graft vascular density was decreased at all investigated implantation sites when compared to endogenous islets. Furthermore, most of the blood vessels were located in the graft connective tissue stroma. Similar results were obtained six months post-transplantation and in cured diabetic animals after one month. In order to evaluate the function of intraportally transplanted islets, we developed a method to retrieve such islets. Enzymatic and mechanic treatment of the liver enabled us to re-isolate the transplanted islets for further in vitro studies. These islets had decreased insulin release, insulin content and glucose oxidation rate when compared to non-transplanted control islets. To understand the role of islet endothelium in the revascularization of transplanted islets we performed angiogenesis microarray studies on islet endothelial cells, from non-cultured, cultured and transplanted islets. We found that the islet endothelium expressed mRNA for both inhibitors and inducers of angiogenesis, and that this expression differed with time. In conclusion, these results provide a useful platform for further studies on the islet endothelium.     

Formation of amyloid in human pancreatic islets transplanted to the liver and spleen of nude mice

In previous studies we have shown that apparently normal human islets, transplanted under the renal capsule of nude mice, frequently and rapidly develop amyloid deposits derived from the beta-cell hormone islet amyloid polypeptide (IAPP). In the present study, we show for the first time that human islets, transplanted into the liver or spleen of nude mice, also develop islet amyloid rapidly. Ultrastructural studies of such islets showed that the first aggregation of IAPP takes place within the beta-cells and that extracellular deposits show up later in the amyloid formation process. We also found that the amount of amyloid formed in human islet grafts placed under the kidney capsule increased with extended (26 weeks) observation time. Moreover, prolonged in vitro culture (14 days) prior to the implantation under the renal capsule seemed to enhance the formation of amyloid in the grafted islets. Since aggregated IAPP has been shown to be toxic to beta-cells, the finding of amyloid deposits in transplanted islets offers a possible explanation to the frequent loss of function of islets transplanted into diabetic patients.     

Engraftment and growth of transplanted pancreatic islets

Transplantation of pancreatic islets may provide a cure for type 1 diabetes. However, this treatment can currently be offered only to very few patients. To improve transplantation success we need to understand better the mechanisms of how the implanted islets survive, grow and/or maintain adequate function. We herein report on our studies to evaluate the factors responsible for the engraftment, i.e. revascularization, reinnervation etc., of transplanted islets and relate these factors to the metabolism and growth of the islets. Graft metabolism can be monitored by microdialysis probes that allow for the measurement of minute amounts of islet metabolites and hormonal products. Growth of the endocrine cells can be stimulated both in vitro before implantation and in vivo post-transplantation. Another problem is rejection of transplanted islets, which may be overcome by the microencapsulation of islets. The knowledge gained by the present studies will enable us to elucidate the optimal treatment of islets to ensure a maximal survival of the transplanted islets, and may be applied also to clinical islet transplantation.     

大囊包被胰岛异种移植治疗糖尿病小鼠的实验研究

为防止胰岛异种移植后的排斥反应，根据免疫隔离原理，采用琼脂糖和胶原包被大鼠胰岛异种并将其植入糖尿病小鼠体内，观察受者的血糖变化。结果显示，接受大囊包被胰岛移植后，９２．３％的糖尿病小鼠血糖恢复正常，在不使用任何免疫抑制的飞速２下，受者正常血糖持续时间达１２５．８±５７．９天，而对照组正常血糖持续时间仅６．７５±２．９９天。受者耐糖曲线与正常对照组相似；     

Microencapsulation of rat islets prolongs xenograft survival in diabetic mice.

ＭｉｃｒｏｅｎｃａｐｓｕｌａｔｉｏｎｏｆｒａｔｉｓｌｅｔｓｐｒｏｌｏｎｇｓｘｅｎｏｇｒａｆｔｓｕｒｖｉｖａｌｉｎｄｉａｂｅｔｉｃｍｉｃｅＺｈｏｕＭａｏｈｕａ周茂华，ＣｈｅｎＤｏｎｇｍｉｎｇ陈东明，ＹａｏＱｉ姚琦，ＸｉａＺｈａｏｊｉ夏兆骥，ＷａｎｇＣｈ...     

Engraftment and Growth of Transplanted Pancreatic Islets

Abstract

Transplantation of pancreatic islets may provide a cure for type 1 diabetes. How—ever, this treatment can currently be offered only to very few patients. To improve transplantation success we need to understand better the mechanisms of how the implanted islets survive, grow and/or maintain adequate function. We herein report on our studies to evaluate the factors responsible for the engraftment, i.e. revascularization, reinnervation etc., of transplanted islets and relate these factors to the metabolism and growth of the islets. Graft metabolism can be monitored by microdialysis probes that allow for the measurement of minute amounts of islet metabolites and hormonal products. Growth of the endocrine cells can be stimulated both in vitro before implantation and in vivo post-transplantation. Another problem is rejection of transplanted islets, which may be overcome by the microencapsulation of islets. The knowledge gained by the present studies will enable us to elucidate the optimal treatment of islets to ensure a maximal survival of the transplanted islets, and may be applied also to clinical islet transplantation.     

Influence of microenvironment on engraftment of transplanted β-cells

Pancreatic islet transplantation into the liver provides a possibility to treat selected patients with brittle type 1 diabetes mellitus. However, massive early β-cell death increases the number of islets needed to restore glucose homeostasis. Moreover, late dysfunction and death contribute to the poor long-term results of islet transplantation on insulin independence. Studies in recent years have identified early and late challenges for transplanted pancreatic islets, including an instant blood-mediated inflammatory reaction when exposing human islets to the blood microenvironment in the portal vein and the low oxygenated milieu of islets transplanted into the liver. Poor revascularization of remaining intact islets combined with severe changes in the gene expression of islets transplanted into the liver contributes to late dysfunction. Strategies to overcome these hurdles have been developed, and some of these interventions are now even tested in clinical trials providing a hope to improve results in clinical islet transplantation. In parallel, experimental and clinical studies have, based on the identified problems with the liver site, evaluated the possibility of change of implantation organ in order to improve the results. Site-specific differences clearly exist in the engraftment of transplanted islets, and a more thorough characterization of alternative locations is needed. New strategies with modifications of islet microenvironment with cells and growth factors adhered to the islet surface or in a surrounding matrix could be designed to intervene with site-specific hurdles and provide possibilities to improve future results of islet transplantation.     

移植胰岛血管内皮细胞GIPR表达的实验研究

目的:研究葡萄糖依赖性胰岛素刺激多肽受体(Glucose-dependent insulinotmpic polypeptide receptor,GIPR)在移植胰岛血管内皮细胞的表达情况.方法:用胰管内灌注、V型胶原酶消化,Ficoll-400梯度离心纯化的方法,获取较纯胰岛后通过门静脉途径移植到糖尿病大鼠肝脏,术后每天给于免疫抑制剂他可莫斯(Taerolimus,FK506)和氯芬酸酯(Mycophenolate mofetil,MMF)灌胃.移植模型分别饲养7、14、40、60d后取材,用免疫组化方法研究GIPR在胰岛血管的表达.结果:移植胰岛内部分血管内皮细胞表达GIPR.结论:GIPR阳性内皮细胞参与了移植物血管重建;新生的胰岛血管具备肝脏血管某些特征,能够被GIP影响.     

聚乙二醇对同种小鼠胰岛移植后抗排斥治疗的影响

目的 探讨聚乙二醇(PEG)包埋小鼠胰岛细胞对同种小鼠胰岛移植物存活的影响,以及其与抗排斥药雷帕霉素共同应用对胰岛移植后抗排斥治疗的影响.方法 选取C57BL/16雄性小鼠皮下预血管化糖尿病模型,行BALB/c小鼠胰岛移植.随机分为6组:A组:正常胰岛移植组.B组:PEG包埋胰岛移植组.C组:正常胰岛移植+雷帕霉素1.5 mg·kg~(-1)·d~(-1)治疗组.D组:PEG包埋胰岛移植+雷帕霉素1.5 mg·kg~(-1)·d~(-1)治疗组.E组:正常胰岛移植+雷帕霉素3 mg·kg~(-1)·d~(-1)治疗组.F组:PEG包埋胰岛移植+雷帕霉素3 mg·kg~(-1)·d~(-1)治疗组.观察小鼠血糖变化,病理检测移植物存活情况.结果 B组胰岛存活时间(25.5±5.9)d较A组(14.7±2.6)d明显延长(P<0.01),C组胰岛存活时间(35.0±3.1)d,D、E、F组胰岛于移植后6周均存活.HE染色下B组较A组炎症反应轻,胰岛结构完整.免疫组化染色显示B组有散在染色增强细胞团而A组未见.结论 PEG包埋胰岛细胞可显著延长移植物的存活时间,并能减少免疫抑制剂雷帕霉素的用量.     

人胰岛的分离纯化和功能评价

目的 应用Ricordi人胰岛分离技术分离和纯化人的胰岛,并进行功能和安全性的评价.方法 获得6例成人尸体胰腺组织供体,采用胶原酶消化法及密度梯度离心法分离和纯化胰岛,并分析胰岛的数量、纯度和活力.采用免疫荧光法分析胰岛内分泌细胞的组成和分布;检测葡萄糖刺激的胰岛素分泌和胰岛移植后的动物血糖水平.并对分离胰岛的安全性指标进行评价.结果 分离纯化后的胰岛数量为(22.9±3.1)万IEQ,纯度为(59.0 ±8.9)%,活力为(89.0±3.0)%.免疫荧光显示,胰岛由4种内分泌细胞组成并呈正常分布.葡萄糖刺激胰岛素释放的刺激指数为8.1 ±4.0.胰岛移植于糖尿病裸鼠后,血糖在3 d后降至正常水平并维持超过30 d.分离胰岛样本的各项安全性指标在规定范围之内.结论 采用Ricordi人胰岛分离技术分离和纯化的胰岛在形态、结构、数量、纯度、活力、体内外功能以及安全性方面都达到临床胰岛移植的标准,为开展临床胰岛移植奠定了基础.