口服胰岛素抑制胰岛β细胞凋亡预防NOD鼠糖尿病

目的: 观察口服胰岛素免疫干预对非肥胖糖尿病(non-obese diabetic, NOD)鼠胰岛炎、β细胞凋亡和糖尿病的影响,并探讨其诱导免疫耐受的机制.方法: 86只NOD雌鼠随机分为胰岛素处理组(n=43)和磷酸盐缓冲液(phosphate buffered saline, PBS)对照组(n=43),从4周龄始每周灌胃人普通胰岛素1mg(70μL)2次,12周后改为每周灌胃1次至30周,对照组予等体积的PBS;于12周龄观察胰岛炎和胰岛β细胞凋亡;检测胰岛Fas和FasL的表达;测定血清IL-4和IFN-γ浓度,以及胰岛内I-Aβg7,IL-1β,IFN-γ,Fas,IL-4,TGF-β mRNA和小肠PP(Peyer's Patch)淋巴结IL-4,IFN-γ,TGF-β mRNA的表达水平.结果: NOD鼠口服胰岛素组30周龄和52周龄时发病率为55.6%和70.4%,分别比PBS对照组(85.7%和96.4%)低(P＜0.05).胰岛素组胰岛炎积分比对照组低,但差异无统计学意义(P＞0.05).胰岛素组胰岛Fas抗原表达和β细胞凋亡率均比PBS对照组低(均P＜0.05).胰岛素组胰岛内I-Aβg7,IFN-γ,IL-1β,Fas mRNA和PP淋巴结IFN-γ mRNA表达均较PBS对照组低(均P＜0.05),而IL-4,TGF-β mRNA表达较对照组高(均P＜0.05);胰岛素组血清IL-4比PBS组高,IFN-γ比PBS组低(均P＜0.05).结论:口服胰岛素能诱导NOD鼠的免疫耐受而预防糖尿病的发生,但不能阻断胰岛炎的进展.口服胰岛素能诱导调节性T细胞产生,使全身和胰岛局部T细胞由Th1向Th2转型,从而抑制Fas介导的β细胞凋亡而预防糖尿病.     

Fas-FasL在NOD小鼠胰岛炎中的作用

目的分析Fas-FasL在NOD小鼠胰岛炎中的作用。方法取32只分属不同周龄的雌性NOD小鼠,观察其血糖、胰岛HE染色、免疫组织化学染色———检测胰岛素、CD8、Fas、FasL的表达。在分析NOD小鼠胰岛炎中以胰岛或相关细胞为研究单位,从而减少了混杂因素的影响。结果雌性NOD小鼠自6周龄起出现胰岛炎,其评分逐渐增加(P<0.0005),14周龄出现糖尿病。随着胰岛炎的加重:胰岛素阳性细胞减少(P<0.0005),与胰岛炎评分呈负相关(P<0.05);Fas 胰岛细胞增加(P<0.0005),与评分呈正相关(P<0.01);FasL 胰岛细胞出现并逐渐增加(P<0.0005),与评分呈正相关(P<0.01);浸润细胞表达FasL、CD8,均逐渐增加(P<0.0005)。胰岛细胞的Fas与胰岛素表达之间呈负相关、胰岛素与FasL呈负相关、Fas与FasL呈正相关,浸润细胞的CD8与FasL表达呈正相关,P值均小于0.01。结论在NOD小鼠胰岛炎中,Fas-FasL可能参与β细胞损伤及自身免疫负调节。     

皮下注射胰岛素抑制胰岛β细胞凋亡预防NOD鼠糖尿病

目的：观察皮下注射胰岛素免疫干预对非肥胖糖尿病（non-obese diabetic,NOD）鼠胰岛炎、B细胞凋亡和糖尿病的影响,并探讨其诱导免疫耐受的机制。方法：60只NOD雌鼠随机分为胰岛素处理组（n=34）和磷酸盐缓冲液（phosphate buffered saline,PBS）对照组（n=28）,分别于4周、12周、20周、28周皮下注射中效胰岛素优泌林N（Humulin N）6U（60μL）＋不完全弗氏佐剂（incomplete Freund＇s adjuvant,IFA）60μL,对照组予PBS（60μL）＋IFA（60μL）。于12周龄观察胰岛炎和胰岛B细胞凋亡;检测胰岛Fas和FasL的表达;测定血清IL-4和IFN-γ浓度,以及胰岛内I-Aβ^x7,IL-1β,IFN-γ,Fas,IL-4 mRNA的表达水平。结果：NOD鼠皮下注射胰岛素加IFA组30周龄和52周龄时发病率仅为21．4％和28．6％,而皮下PBS加IFA组为71．4％和85．7％（P〈0．05）。胰岛素组胰岛炎积分比对照组低,但差异无统计学意义（P〉0．05）。胰岛素组胰岛Fas抗原表达和B细胞凋亡率均比PBS对照组低（均P〈0．05）。胰岛素组胰岛内I-Aβ^x7,IFN-γ,IL-1β,FasmRNA表达较PBS对照组低（均P〈0．05）,而IL-4mRNA表达较对照组高（P〈0．05）;胰岛素组血清IL-4比PBS组高,IFN-γ比PBS组低（均P〈0．05）。结论：皮下注射胰岛素能诱导NOD鼠的免疫耐受而预防糖尿病的发生,但不能阻断胰岛炎的进展。皮下注射胰岛素能诱导调节性T细胞产生,使全身和胰岛局部T细胞由,Th1向Th2转型,从而抑制Fas介导的B细胞凋亡而预防糖尿病。     

胰岛素早期强化治疗对发病NOD小鼠胰岛炎及bax、bcl-2表达的影响

目的探讨胰岛素早期强化治疗对发病非肥胖糖尿病(NOD)小鼠胰岛炎及对胰岛细胞凋亡与再生的影响。方法选取近期发病NOD小鼠12只,随机平均分为A、B两组,A组给予胰岛素早期强化治疗,B组为发病未治疗组。同时选取同周龄未发病小鼠6只为C组。B和C组分别于分组当日即开始予PBS缓冲液对照治疗。B组于20 d处死,A和C组于60 d处死。HE染色观察各组小鼠胰岛炎性积分,免疫组化观察小鼠胰岛bax、bcl-2蛋白的表达。结果 A组小鼠糖尿病症状得到明显控制,其胰岛炎性积分显著低于B组(P<0.05),与C组相比差异无统计学意义(P>0.05)。A组bax表达低于B组,但差异无统计学意义(P>0.05),与C组相比差异有统计学意义(P<0.05)。A组bcl-2表达显著高于B组和C组(P<0.05)。结论胰岛素早期强化治疗能够减轻胰岛炎症,减少细胞凋亡,促进胰岛细胞再生。     

脂质体与完全弗氏佐剂预防NOD鼠胰岛炎探讨

目的 :探讨完全弗氏佐剂 (CFA)、不完全弗氏佐剂 (IFA)、大复层脂质体 (LML)、小单层阳离子脂质体(DOTAP)对NOD鼠胰岛炎和糖尿病发病的影响。方法 :①将 3周龄的NOD雌鼠随机分为 3组 ,分别给予CFA后脚板注射 (n =16 ) ,IFA和PBS乳化后腹腔注射 (n =16 ) ,单独PBS后脚板注射 (n =16 )。观察 12周龄胰岛病理及 30周龄糖尿病发病情况。②将 3周龄的NOD雌鼠随机分为 3组 ,分别给予大复层脂质体 (LML) (n =13) ,小单层阳离子脂质体 (DOTAP) (n =13) ,单独PBS腹腔注射 (n =13) ,同上观察胰岛病理及糖尿病发病情况。结果 :①CFA后脚板注射能明显降低胰岛炎计分 ,减少糖尿病的发生。 30周龄时 ,CFA组的发病率明显低于PBS后脚板注射对照组 (分别为9 2 %和 81 8% ,P =0 .0 0 1)。 12周龄时 ,CFA组胰岛炎计分明显低于对照组 [分别为 (0 0 5± 0 0 2 )和 (0 5 4± 0 11) ,P<0 .0 0 1]。②LML腹腔注射能明显降低胰岛炎计分。 12周龄时 ,LML组胰岛炎计分明显低于PBS腹腔注射对照组 [分别为 (0 16± 0 0 2 )和 (0 5 8± 0 0 6 ) ,P <0 .0 0 1]。 30周龄时 ,LML组糖尿病发生率为 6 0 % ,对照组为 90 % ,两组间无统计学差异。③在预防胰岛炎的作用上 ,CFA优于LML。结论 :CFA后脚板注射可预防NOD鼠发生糖尿病并减     

人谷氨酸脱羧酶65 DNA疫苗预防非肥胖糖尿病小鼠糖尿病的机制探讨

目的　探讨人谷氨酸脱羧酶 6 5 (GAD6 5 )DNA疫苗预防非肥胖糖尿病 (NOD)小鼠糖尿病的作用机制。方法　 (1) 6 2只 4周龄NOD雌鼠分为PBS(2 1只 )、PcDNA(2 0只 )、GAD6 5 (2 1只 ) 3组 ,由胫前肌分别注射PBS、质粒PcDNA3 1、人GAD6 5DNA疫苗 5 0 μg ,1周后重复 1次。观察 30周龄的累积糖尿病发病率。 (2 )各组取 12周龄未发病NOD鼠 (n =10 )胰腺HE染色观察胰岛炎 ;并用末端脱氧核糖核酸缺口标记法 (TUNEL)加SABC法检测胰岛 β细胞凋亡 ;ELISA法测定血清、脾细胞培养上清干扰素γ(IFN γ)和白细胞介素 4 (IL 4 )水平 ;RT PCR半定量检测脾脏IL 4、IFN γ和核因子NF ATc、NF ATpmRNA表达水平。结果　 (1) 30周龄时 ,PBS、PcDNA、GAD6 5组发病率分别为 95 2 %、80 0 %、6 1 9%。GAD6 5组发病率低于PBS组 (P =0 0 0 8)。 (2 ) 12周龄时GAD6 5组胰岛炎积分 (0 99± 0 71)和胰岛 β细胞凋亡率 (0 75 % )均低于PBS组 (2 16± 0 78,P =0 0 0 1;8 97% ,P=0 0 14 )和PcDNA组 (1 72± 0 5 9,P =0 0 2 7;2 6 5 % ,P =0 0 2 3)。GAD6 5组脾脏NF ATc、IL 4mRNA相对吸光度值及血清IL 4水平分别为 1 93± 0 34、0 70± 0 16、36 pg/ml± 8pg/ml,显著高于PBS组 (0 79± 0 15、0 4 9± 0 11、19pg/ml     

完全弗氏佐剂抑制NOD鼠胰岛β细胞凋亡及其机制

目的:探讨完全弗氏佐剂( complete Freund’s adjuvant, CFA)对非肥胖糖尿病( nonobese dia-betic, NOD)鼠胰岛β细胞凋亡及凋亡相关基因Fas,FasL和Bcl-x表达的影响。方法:将4周龄NOD雌鼠随机分为CFA组(n=5)和生理盐水( NS)对照组(n=5 ) ,给CFA组鼠后脚板注射50μLCFA,对照者鼠后脚板注射等量NS。监测血糖,若血糖连续2 d≥11.1 mmol /L即诊断为糖尿病。当NOD鼠发生糖尿病或至30周龄时,处死动物,取胰腺组织制成薄切片,HE染色观察胰岛炎,采用末端脱氧核苷酸转移酶介导的脱氧尿苷三磷酸缺口末端标记( TUNEL)及ABC免疫组织化学双标记染色观察并计数凋亡的胰岛β细胞,ABC免疫组织化学法染色观察并记数Fas,FasL和Bcl-x表达阳性细胞。结果:至NOD鼠30周龄时,CFA处理组鼠无1只发生糖尿病,对照组鼠有3只发生糖尿病;CFA处理组的胰岛炎积分低于NS对照组(1.820±0.962 vs. 3.020±1.040,P<0.05 ) ;CFA处理组胰岛β细胞凋亡率、Fas阳性细胞率、FasL阳性细胞率均低于NS对照组[ (10.2±2.8) % vs. (15.9±6.5) %,(54.9±14.5)% vs.(75.7±12.9) %,(20.3±10.4) % vs. (27.9±12.0) %,P<0.05] ,Bcl-x阳性细胞率高于NS对照组[ (74.9±10.7) % vs. (66.0±18.3) %,P<0.05]。结论:CFA能够减轻NOD鼠胰岛β细胞凋亡,其机制与减少促凋亡基因Fas和FasL表达及增加抑制凋亡基因Bcl-x表达有关。     

Somatostatin receptor expression and biological functions in endocrine pancreatic cells: review based on a doctoral thesis

Type 1 diabetes is resulting from the selective destruction of insulin-producing betacells within the pancreatic islets. Somatostatin acts as an inhibitor of hormone secretion through specific receptors (sst1-5). All ssts were expressed in normal rat and mouse pancreatic islets, although the expression intensity and the co-expression pattern varied between ssts as well as between species. This may reflect a difference in response to somatostatin in islet cells of the two species. The Non-Obese Diabetic (NOD) mouse model is an experimental model of type 1 diabetes, with insulitis accompanied by spontaneous hyperglycaemia. Pancreatic specimens from NOD mice at different age and stage of disease were stained for ssts. The islet cells of diabetic NOD mice showed increased islet expression of sst2-5 compared to normoglycemic NOD mice. The increase in sst2-5 expression in the islets cells may suggest either a contributing factor in the process leading to diabetes, or a defense response against ongoing beta-cell destruction. Somatostatin analogues were tested on a human endocrine pancreatic tumour cell line and cultured pancreatic islets. Somatostatin analogues had an effect on cAMP accumulation, chromogranin A secretion and MAP kinase activity in the cell line. Treatment of rat pancreatic islets with somatostatin analogues with selective receptor affinity was not sufficient to induce an inhibition of insulin and glucagon secretion. However, a combination of selective analogues or non-selective analogues via costimulation of receptors can cause inhibition of hormone production. For insulin and glucagon, combinations of sst2 + sst5 and sst1 + sst2, respectively, showed a biological effect. In summary, knowledge of islet cell ssts expression and the effect of somatostatin analogues with high affinity to ssts may be valuable in the future attempts to influence beta-cell function in type 1 diabetes mellitus, since down-regulation of beta-cell function may promote survival of these cells during the autoimmune attack.     

脂质体与完全费氏佐剂预防NOD鼠胰岛炎探讨

OBJECTIVE: To explore the effects of complete Freund's adjuvant (CFA), incomplete Freund's adjuvant(IFA), large multilamellar liposome (LML) and small cationic liposome (DOTAP) on insulitis and diabetes. METHODS: 1. 3-week-old non-obese diabetic(NOD) female mice were randomly divided into 3 groups: CFA group (injected subcutaneously in the hind footpad, n = 16), IFA group (injected intraperitoneally, n = 16) and PBS group (injected subcutaneously in the hind footpad, n = 16). Three mice from each group (9 in total) were killed at the age of 12 weeks for the analysis of pancreatic pathology, and the others were not killed until they were 30 weeks old for diabetes incidence. 2. 3-week-old NOD female mice were randomly divided into 3 groups and injected intraperitoneally with LML (n = 13), DOTAP (n = 13) and PBS (n = 13), respectively. The insulitis score and diabetes incidence were estimated in the same way. RESULTS: 1. CFA injected subcutaneously in the hind footpad could significantly reduce the insulitis score and decrease diabetes incidence in NOD mice. At the age of 30 weeks, the incidence of diabetes in the CFA group was lower than that in the PBS group (injected subcutaneously in the hind footpad) (9.2% vs 81.8%, P = 0.001). At the age of 12 weeks, the insulitis score in the CFA group was lower than that in the control group [(0.05 +/- 0.02) vs (0.54 +/- 0.11), P < 0.001]. 2. LML injected intraperitoneally could significantly reduce the insulitis score in NOD mice. At the age of 12 weeks, the insulitis score in the LML group was lower than that in the PBS control group (injected intraperitoneally) [(0.16 +/- 0.02) vs (0.58 +/- 0.06), P < 0.001]. At the age of 30 weeks, there were no significant differences in the diabetes incidence between the LML group and the PBS group (60% vs 90%). 3. The protective effect of CFA was better than that of LML in NOD mice. CONCLUSION: CFA injected subcutaneously in the hind footpad may prevent NOD mice from developing diabetes and reduce the insulitis severity. Although the protective effect of CFA is better than that of LML, LML can lessen the insulitis severity and may become a new preventive strategy in NOD mice.     

Expression of monocyte chemoattractant protein-1 in the pancreas of mice

Background Type 1 diabetes has been recognized as an organ specific autoimmune disease owing to the immune destruction of pancreatic islet β cells in genetically susceptible individuals. In both human and rodent models of type 1 diabetes, such as nonobese diabetic (NOD) mice, biobreeding rats, the disease has a distinct stage characterized by immune cells infiltrating in the pancreas (insulitis). The major populations of infiltrating cells are macrophages and T lymphocytes. Therefore, immune cell infiltration of pancreatic islets may be a crucial step in the pathogenesis of type 1 diabetes. Monocyte chemoattractant protein-1 can specifically attract monocytes in vivo. Interferon induced protein-10 has chemoattractant effects on the activated lymphocytes. In this study, we analysed the expression of monocyte chemoattractant protein-1 in the pancreas of mice and interferon inducible protein-10 mRNA in the pancreas of NOD mice, and discussed their possible role in the pathogenesis of type 1 diabetes. Methods The immunohistochemical method and immunoelectronmicroscopy were used to evaluate the expression of monocyte chemoattractant protein-1 in the pancreas of NOD mice and BALB/c mice. RT-PCR was used to evaluate the expression of monocyte chemoattractant protein-1 and interferon inducible protein mRNA in NOD mice.Results Monocyte chemoattractant protein-1 was positive in the pancreas of NOD mice, whereas negative in the pancreas of BALB/C mice. RT-PCR showed that monocyte chemoattractant protein-1 and interferon inducible protein-10 mRNA could be found in the pancreas of NOD mice. Immunoelectronmicroscopy demonstrated that monocyte chemoattractant protein-1 was produced by β cells and stored in the cytoplasm of the cells.Conclusions Pancreatic islet β cells produce monocyte chemoattractantprotein-1 in NOD mice. Monocyte chemoattractant protein-1 may play an important part in the pathogenesis of type 1 diabetes by attracting monocytes/macrophages to infiltrate pancreatic islets.     

人GLP-1(7-36)酰胺对非肥胖型糖尿病小鼠胰岛炎的影响

目的通过观察人胰高糖素样肽1（GLP-1）刺激后非肥胖型糖尿病（NOD）小鼠胰岛组织形态学的变化,研究GLP-1对NOD 1型糖尿病小鼠胰岛炎的影响。方法 GLP-1治疗组小鼠用微型渗透泵皮下持续泵入人GLP-1,对照组小鼠泵入生理盐水,4周后将其胰腺组织做HE染色、5-溴脱氧尿嘧啶核苷（Br-dU）/胰岛素双重免疫染色及导管细胞角蛋白（DCK）/胰岛素双重免疫荧光染色,观察小鼠胰岛炎的变化及胰岛β细胞的复制和胰腺导管上皮β细胞的新生。结果与对照组相比,GLP-1治疗组NOD小鼠胰岛单核细胞浸润明显减轻,胰岛炎评分明显下降（P〈0.001）。GLP-1治疗组胰岛可见较多BrdU阳性的β细胞和胰岛素阳性的导管上皮细胞,而在对照组几乎看不到。结论人GLP-1持续刺激NOD小鼠后,可使1型糖尿病小鼠胰岛炎减轻并促进β细胞再生。     

The H1-receptor antagonist cetirizine ameliorates high-fat diet-induced glucose intolerance in male C57BL/6 mice,but not diabetes outcome in female non-obese diabetic (NOD) mice

Background It has been proposed that the histamine 1-receptor (H1-receptor) not only promotes allergic reactions, but also modulates innate immunity and autoimmune reactions. In line with this, we have recently reported that the H1-receptor antagonist cetirizine partially counteracts cytokine-induced beta-cell signaling and destruction. Therefore, the aim of this study was to determine whether cetirizine affects diabetes in NOD mice, a model for human type 1 diabetes, and glucose intolerance in high-fat diet C57BL/6 mice, a model for human glucose intolerance.Methods Female NOD mice were treated with cetirizine in the drinking water (25 mg/kg body weight) from 9 until 30 weeks of age during which precipitation of diabetes was followed. Male C57BL/6 mice were given a high-fat diet from 5 weeks of age. When the mice were 12 weeks of age cetirizine was given for 2 weeks in the drinking water. The effects of cetirizine were analyzed by blood glucose determinations, glucose tolerance tests, and insulin sensitivity tests.Results Cetirizine did not affect diabetes development in NOD mice. On the other hand, cetirizine treatment for 1 week protected against high-fat diet-induced hyperglycemia. The glucose tolerance after 2 weeks of cetirizine treatment was improved in high-fat diet mice. We observed no effect of cetirizine on the insulin sensitivity of high-fat diet mice.Conclusion Our results suggest a protective effect of cetirizine against high-fat diet-induced beta-cell dysfunction, but not against autoimmune beta-cell destruction.     

NOD 小鼠胰岛的分离及其在体内外的生物学特性

目的 建立分离纯化非肥胖性糖尿病(NOD)小鼠胰岛的方法,并对其体内外生物学特性进行研究?方法 采用改良的胶原酶消化结合Ficoll 密度梯度离心方法,分离纯化NOD 小鼠胰岛?应用体外糖刺激实验检测分离纯化的胰岛功能,以及通过监测移植小鼠的血糖?体重变化及糖耐量实验对移植胰岛的体内生物学功能进行分析,并通过HE 染色和免疫荧光染色检测肾被膜下移植胰岛的存活情况?结果 胰岛产率为(116 ±12)个胰岛/胰腺,纯度>90%?体外糖刺激实验结果显示,NOD 小鼠胰岛的糖刺激胰岛素释放水平明显低于KM 小鼠胰岛?胰岛移植实验显示,移植胰岛能有效改善糖尿病小鼠的血糖?体重和糖耐量,但改善作用一般仅能维持2 周左右?HE 染色和免疫荧光染色结果显示,肾被膜下可见胰岛素阳性的胰岛细胞团,并且在残存的移植胰岛细胞团周围存在大量淋巴细胞浸润?结论 通过改良的小鼠胰岛分离方法可由NOD 小鼠分离得到大量较高纯度的胰岛,可用于今后探索如何阻断自身免疫损伤保护移植胰岛的研究?     

The H1-receptor antagonist cetirizine ameliorates high-fat diet-induced glucose intolerance in male C57BL/6 mice,but not diabetes outcome in female non-obese diabetic (NOD) mice

Abstract

Background. It has been proposed that the histamine 1-receptor (H1-receptor) not only promotes allergic reactions, but also modulates innate immunity and autoimmune reactions. In line with this, we have recently reported that the H1-receptor antagonist cetirizine partially counteracts cytokine-induced beta-cell signaling and destruction. Therefore, the aim of this study was to determine whether cetirizine affects diabetes in NOD mice, a model for human type 1 diabetes, and glucose intolerance in high-fat diet C57BL/6 mice, a model for human glucose intolerance.

Methods. Female NOD mice were treated with cetirizine in the drinking water (25 mg/kg body weight) from 9 until 30 weeks of age during which precipitation of diabetes was followed. Male C57BL/6 mice were given a high-fat diet from 5 weeks of age. When the mice were 12 weeks of age cetirizine was given for 2 weeks in the drinking water. The effects of cetirizine were analyzed by blood glucose determinations, glucose tolerance tests, and insulin sensitivity tests.

Results. Cetirizine did not affect diabetes development in NOD mice. On the other hand, cetirizine treatment for 1 week protected against high-fat diet-induced hyperglycemia. The glucose tolerance after 2 weeks of cetirizine treatment was improved in high-fat diet mice. We observed no effect of cetirizine on the insulin sensitivity of high-fat diet mice.

Conclusion. Our results suggest a protective effect of cetirizine against high-fat diet-induced beta-cell dysfunction, but not against autoimmune beta-cell destruction.     

单核细胞趋化蛋白-1在非肥胖糖尿病小鼠胰腺中的表达

目的 通过观察单核细胞趋化蛋白-1（Monocyte Chemoattractant Protein-1）在1型糖尿病动物模型NOD小鼠胰腺中的表达，探讨其在1型糖尿病胰岛炎发病机制中的作用。方法 应用免疫组化SABC法和免疫电镜评价MCP-1在NOD小鼠和BALB／C小鼠胰腺中的表达，应用H＆E染色光镜下评价胰岛免疫细胞浸润。结果 免疫组化结果表明：NOD小鼠胰腺中MCP-1呈阳性表达，而对照组无MCP-1表达。免疫电镜进一步显示：MCP-1由胰岛β细胞产生并存在于细胞质中。结论 MCP-1主要由胰岛β细胞产生。MCP-1通过招募单核／巨噬细胞浸润胰岛而在1型糖尿病发病机制中起重要作用。     

人GLP-1(7-36)酰胺对非肥胖型糖尿病小鼠胰岛β细胞凋亡的影响

目的探讨人胰高糖素样肽1(GLP-1)对非肥胖型糖尿病(NOD)小鼠胰岛β细胞凋亡的影响。方法 GLP-1治疗组小鼠用微型渗透泵皮下持续泵入人GLP-1,对照组小鼠泵入生理盐水,4周后将其胰腺组织做HE染色、TUNEL/胰岛素双重免疫荧光染色,显微镜下观察小鼠胰岛炎的变化及胰岛β细胞的凋亡情况。结果与对照组相比,GLP-1治疗组小鼠胰岛单核细胞浸润明显减轻,胰岛炎评分明显下降(P<0.001)。在对照组小鼠胰腺组织切片中观察到较多凋亡β细胞,而在GLP-1治疗组却很少见到。GLP-1治疗组小鼠胰岛β细胞凋亡率与对照组小鼠相比明显下降(0.07±0.01%vs0.26±0.02%,P<0.001)。结论人GLP-1持续刺激NOD小鼠后,可使1型糖尿病小鼠胰岛炎减轻并抑制β细胞凋亡。     

Investigation of long-term preservation of pancreatic islets

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CFA对NOD鼠胰岛素和糖尿病的预防机制研究

The degrees of insulitis, the incidence of diabetes, and the counts of alpha,beta and delta cells in islets were studied by morphological method and avidin-biotin complex immunohistochemical method in complete Freund's adjuvant(CFA) or normal saline(NS)-treated non-obese diabetic(NOD) female mice. The results showed: The incidences of in-insulitis and the scoring means were significantly lower in CFA-treated mice than those in NS-treated ones; none of 5 CFA-treated mice and 3 out of 5 NS-treated ones developed diabetes. The positive rates of alpha, and delta cells were significantly lower in CFA-treated mice than those in NS-treated ones, but the positive rate of beta cell was significantly higher in CFA-treated mice than that in NS-treated ones. The correlations were found among the scores of insulitis and the positive rates of alpha, beta, delta cells in islets (r alpha = 0.475, r beta = -0.878, r delta = 0.869). The results indicate that CFA may lessen the degrees of insulitis and the incidence of diabetes. Its effects might be related to lessen the damage of beta cell in islets.     

NOD小鼠糖尿病病症的初步观察

对126只NOD小鼠自发性糖尿病发病情况观察，52周后雌性发病率为50％、雄性发病睾为28．3％。雌性发病早于雄性，发病期小鼠尿糖、血糖水平升高，发病后2～5周死亡。主要病理学特征表现为胰岛炎及胰岛萎缩等。     

咯利普兰诱发NOD小鼠bcl-2、bax在脾脏、胰腺的差异性表达

目的 通过检测bcl-2、bax在脾脏、胰腺的表达旨在探讨IV型磷酸二酯酶抑制剂咯利普兰(rolipram)对NOD小鼠的免疫干预机制。方法 将60只体重相近的4周龄雌性NOD小鼠随机分为干预、对照两组，每组30只。干预组腹腔注射咯利普兰(8mg／kg)，每日两次；对照组注射等次等量的PBS。两组小鼠均于实验第1和第14天备注射1次环磷酰氨(200mg／kg)以加速糖尿病的进程。实验第30天处死，HE染色观察胰岛炎；免疫组化检测bcl-2，bax在胰岛、脾脏的表达。结果 咯利普兰处理组在胰岛过表达bcl—2基因(P＜0．01)，而在脾脏过表达bax基因(P＜0．01)；PBS对照组与咯利普兰处理组相反。结论 咯利普兰在胰腺组织能促进bcl—2的表达以抑制胰岛β细胞的凋亡；而在淋巴系统却能促进比的表达以加速T淋巴细胞的凋亡从而减轻自身免疫反应。