抗氧化微量营养素对T1DM小鼠Insulin基因表达的定量研究

目的探讨联合抗氧化微量营养素(antioxidant micronutrients,AM)对胰岛β细胞insulin基因转录与翻译水平表达的影响,为应用天然抗氧化物的互补生物学作用,提高糖尿病状态下的胰岛素基因表达提供分子水平科学依据。方法应用MLDS(multiply low dosage of streptozotocin)方法制备T1DM小鼠模型,分别联合添加4种AM(Se+VE+V+Cr)和7种AM(Se+VE+V+Cr+VC+硫辛酸+烟酰胺)进行干预,运用ISH、IHC及图像分析技术系统观察其对insulin基因转录与翻译水平表达变化的影响。结果联合补充AM可明显增加T1DM模型小鼠胰岛β细胞insulin mRNA表达水平(P<0.05～0.01),提高胰岛β细胞insulin免疫组化阳性反应产物量(P<0.05～0.01),可分别在转录与翻译水平明显上调胰岛素基因的表达水平。结论 AM联合生物学效应可在转录与翻译水平上调T1DM时insulin基因表达,提高内源性胰岛素水平,拮抗糖尿病关键发病中间环节。     

联合抗氧化微量营养素对T1DM小鼠心、脑、肾、肝组织氧化应激状态的影响

目的比较不问抗氧化微量营养紊组合对实验性糖尿病小鼠心、脑、肾、肝组织氧化应激状态的干预作用。为应用抗氧化微量营养索防止糖尿病合并症提供科学依据。方法应用MLDS方法制备小鼠T1DM模型，分别添加4种（Se、VE、V、Cr）或7种（Sc、VE、V、Cr、VC、烟酰胺、赖氨酸）抗氧化微量营养紊，比较不同抗氧化微量营养索组合对糖尿病时心、脑、肾、肝组织抗氧化酶GSH-Px、SOD活性及自由基代谢产物MDA的影响。结果联合添加微量营养素的两组糖尿病小鼠心、脑、肾、肝组织GSH-Px、SOD活性不同程度地明显增高，MDA含量降低，但4种微量营养素添加组与7种微量营养素添加组之间酶活力水平与MDA含量未见明显差别。结论联合添加抗氧化微量营养素可明显减轻糖尿病小鼠心、脑、肾、肝组织氧化应激状态，可能对糖尿病合并症具有防治作用。     

链脲佐菌素对鼠胰腺病理学的影响

目的:观察链脲佐菌素致糖尿病鼠胰腺病理学变化,探讨链脲佐菌素致糖尿病的机制。方法:采用腹腔注射链脲佐菌素建立糖尿病大鼠、小鼠模型并检测血糖、C肽水平,取胰腺HE染色,观察其病理形态变化。结果:大鼠、小鼠腹腔注射链脲佐菌素后血糖均明显升高,C肽水平下降。成模大鼠、小鼠胰岛缩小,β细胞数量减少。结论:链脲佐菌素直接破坏胰岛β细胞,使β细胞数量减少,导致糖尿病的发生。     

生长分化因子11对db/db糖尿病小鼠胰岛β细胞功能的保护作用及机制研究

目的探讨生长分化因子11(GDF11)对瘦素受体基因纯合突变(db/db)糖尿病小鼠胰岛β细胞的保护作用及影响机制。方法将20只8周龄的C57B/6J野生型小鼠制备为db/db糖尿病模型,并随机分为GDF11组和DM组,每组各10只;GDF11组小鼠给予GDF11重组蛋白注射,DM组小鼠给予磷酸盐缓冲液(PBS)注射,连续注射6周;并选取10只同龄正常小鼠作为对照组(NC组),给予6周PBS干预。观察GDF11对小鼠生理生化指标、胰岛β细胞功能以及胰岛Smad2、P-Smad2表达水平的影响。结果经GDF11干预后,db/db糖尿病小鼠的空腹血糖(FBS)、糖化血红蛋白(Hb A1C)、总胆固醇(TC)、三酰甘油(TG)、游离脂肪酸(FFA)均明显低于DM组及NC组小鼠(P<0.05);db/db糖尿病小鼠的糖耐量水平显著改善,GDF11组小鼠的血清胰岛素、血清胰升糖素均明显低于DM组(P<0.05),且均高于NC组(P<0.05);GDF11组小鼠的胰岛内胰岛素的水平明显高于DM组(P<0.05),但低于NC组(P<0.05);DM组与GDF11组小鼠的胰岛内胰升糖素无显著差异(P>0.05),且均高于NC组(P<0.05);经实时荧光定量PCR检测发现GDF11组小鼠胰岛胰十二指肠同源异型盒基因(Pdx-1)、亮氨酸拉链蛋白Maf家族A(MafA)、Nk同源异型盒基因家族6.1(Nkx6.1)、Insulin2基因表达上调;小鼠的p-Smad2、Smad2蛋白水平明显高于NC组小鼠(P<0.05)。结论GDF11可控制糖尿病小鼠胰升糖素分泌水平,调节β细胞转录因子表达,改善β细胞功能和含量,促进胰岛素的分泌合成,从而延缓糖尿病的发生和发展;GDF11对胰岛β细胞的保护作用可能与胰岛Smad2信号通路密切相关。     

间-α-抑制因子是严重脓毒症潜在介质和临床预警指标

线粒体功能障碍是细胞凋亡的主要原因。以往研究发现，一种新型抗氧化多肽（SS-31）作用靶点位于线粒体内膜，对神经元细胞及其他类型细胞具有抗氧化损伤的作用。最近美国研究人员发现，SS-31可以穿透完整的小鼠胰岛细胞，减少胰岛细胞凋亡，促进胰岛细胞分裂．从而保护胰岛细胞移植术后的胰腺功能。研究者认为，对供体小鼠的胰腺进行SS-31预处理和在分离胰岛细胞时填加SS-31是胰岛分离的最佳方法。流式细胞术分析显示，在体外人胰岛细胞培养基上加入SS-31能减少胰岛细胞凋亡，增强胰岛细胞活性。研究人员对200只同源性糖尿病小鼠进行了胰岛细胞移植术（肾被膜下移植），SS-31组小鼠血糖浓度恢复正常，无SS-31组小鼠血糖浓度显著升高。因此认为，应用SS-31可以有效扩大胰岛细胞移植的供体范围，使胰岛分离更完善，降低1型糖尿病患者受体对胰岛的排斥。     

重组人生长激素对糖尿病小鼠胰岛β细胞功能的保护作用机制分析

目的探讨重组人生长激素(rh GH)对糖尿病小鼠胰岛β细胞功能的影响,并对其可能存在的保护机制进行研究。方法选择30只小鼠采取高糖高脂饲养以及链脲佐菌素(35 mg/kg)建模2型糖尿病模型,采用随机数字表法均分为对照组、模型组、实验组。实验组小鼠采取皮下注射rh GH(0. 3 IU/kg),模型组及对照组小鼠注射等体积生理盐水,给药周期7 d。检测干预0 d、1 d、4 d、7 d时间点时各组小鼠血糖含量,酶联免疫法检测各组小鼠血清胰岛素、胰高血糖素、甘油三酯(TG)、总胆固醇(TC)水平以及胰岛组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSHPx)、丙二醛(MDA)水平以及肿瘤坏死因子-α(TNF-α)、白介素-6 (IL-6)水平。HE染色观察胰岛组织病理学变化,采用TUNEL法及RT-PCR分别检测胰岛β细胞凋亡及Bcl-2、Bax表达水平。结果在0 d、1 d、4 d、7 d时,模型组小鼠血糖含量均低于对照组(P 0. 05),且在1 d、4 d、7 d时实验组小鼠血糖水平均低于模型组(P 0. 05);模型组小鼠TG、TC、胰岛素及胰高血糖素均明显高于对照组(P 0. 05),且实验组小鼠血清胰岛素、胰高血糖素、TG与TC含量均低于模型组(P 0. 05);实验组小鼠胰岛组织中TNF-α、IL-6及MDA水平低于模型组(P 0. 05),而SOD、GSH-Px含量明显高于模型组(P 0. 05); HE染色结果显示模型组小鼠胰岛组织排列紊乱、细胞大小不均匀且炎性细胞浸润,实验组小鼠胰岛组织受损程度较模型组轻;实验组小鼠胰岛β细胞凋亡率低于模型组,RT-PCR结果显示实验组小鼠胰岛β细胞中的Bcl-2表达量高于模型组(P 0. 05)、Bax达量低于于模型组(P 0. 05)。结论 rh GH可以降低糖尿病小鼠血糖、血脂、胰岛素水平,降低胰岛β细胞凋亡率,可能与促进Bcl-2表达、抑制Bax表达量、减少氧化应激及炎性因子水平有关。     

狗胆对实验性糖尿病小鼠治疗作用的研究

目的 观察狗胆对实验性糖尿病小鼠的治疗作用。方法 给动物灌胃给药，用四氧嘧啶制备实验性糖尿病小鼠模型。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 狗胆对四氧嘧啶性糖尿病小鼠的胰岛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 狗胆对实验性糖尿病小鼠具有治疗作用。     

抗氧化微量营养素对糖尿病小鼠细胞因子基因表达的调控作用

目的　研究抗氧化微量营养素 (Antioxidantmicronutrients,AM)对糖尿病小鼠细胞因子基因表达调控作用 ,寻找AM作用的敏感基因 ,探索防治糖尿病的分子生物学策略。方法　通过腹腔注射 2 %四氧嘧啶制备IDDM模型 ,经灌胃方法联合给予硒 (Se)、维生素E(VE)、钒 (V)和铬 (Cr) ,应用流式细胞仪测定外周血淋巴细胞表达IL 2、IL 10、IFN γ和TNF α细胞数百分比以及脾活性氧 (ROS)含量。结果　IDDM模型组小鼠外周血表达IL 2和IL 10水平明显低于AM组和正常组 (P <0 0 1) ;而表达IFN γ水平明显高于其他两组 (P <0 0 1) ;各组表达TNF α无明显差异 (P >0 0 5 ) ;IDDM模型组脾ROS含量明显增高 (P <0 0 1) ,AM组脾ROS含量较模型组明显降低 (P <0 0 1)。结论　联合应用AM可上调糖尿病小鼠IL 2、IL 10基因表达 ,下调IFN γ基因表达 ,并可降低糖尿病小鼠脾中ROS含量 ,从而起到拮抗糖尿病的作用。     

Betatrophin对1型糖尿病小鼠胰岛β细胞功能的保护作用研究

目的探究胰岛再生激素(betatrophin)对1型糖尿病(T1DM)小鼠胰岛β细胞功能的保护作用。方法选取135只小鼠,随机数字表法分为对照组、模型组、干预组各45只。模型组、干预组持续5 d腹腔注射链脲佐菌素溶液制备T1DM小鼠模型,对照组不做任何处理,干预组建模成功即刻经尾静脉注射betatrophin过表达腺病毒。分析各组胰岛β细胞免疫组化染色情况,并比较三组小鼠betatrophin蛋白水平、胰岛素释放试验结果及糖代谢指标、脂代谢指标。结果干预组betatrophin蛋白水平明显高于模型组、对照组(P 0. 05);干预组PAS染色可见胞浆内紫红色,而模型组无紫红色染色;干预组、模型组T1DM建模成功后胰岛β细胞体积、产物数量较对照组明显小,干预组干预后胰岛β细胞染色强度明显小于模型组,但产物数量较模型组多;干预组、对照组注射胰岛素后0 min、30 min、60 min、90 min、120min血糖水平明显低于模型组(P 0. 05),即干预组血糖对胰岛素敏感性大于模型组;与模型组比较,干预组、对照组空腹血糖、空腹胰岛素、2 h血糖、2 h胰岛素、总胆固醇(TC)、甘油三酯(TG)、血清总胆固醇(TC)、低密度脂蛋白(LDLC)明显降低,高密度脂蛋白(HDL-C)明显升高,差异有显著性(P 0. 05)。结论 Betatrophin可有效保护T1DM小鼠胰岛β细胞功能并促进胰岛素分泌,在提高小鼠对胰岛素敏感性及调节糖脂代谢方面有积极作用,或可为T1DM新型治疗策略提供参考。     

糖尿病小鼠理想的胰岛移植部位

背景:胰岛移植到糖尿病小鼠不同部位影响胰岛移植成功率。目的:比较糖尿病小鼠小网膜、肾被膜和腋窝3个部位胰岛移植效果,探索一个更理想的移植部位。方法:应用淋巴细胞分离液分离纯化BALB/c小鼠胰岛;将胰岛移植到造模成功的糖尿病C57BL/6小鼠,按照不同的移植部位小网膜、肾被膜和腋窝进行对比观察。结果与结论:分离纯化后获得高纯度胰岛,每只供体可获得胰岛(102±4)个,并具有良好生物活性;胰岛移植到糖尿病小鼠小网膜、肾被膜和腋窝3个部位后,均能降低血糖至正常范围,移植到小网膜与肾被膜的血糖值差异无显著性意义(P>0.05),但均低于腋窝血糖值(P<0.05)。移植后第7天,苏木精-伊红染色见小网膜部位移植胰岛形态基本完整,肾被膜部位移植胰岛形态不规则,腋窝部位移植物胰岛完全被破坏,伴炎症细胞浸润,小网膜和肾被膜降血糖效果优于腋窝。说明小网膜血供充足容量大,能够接纳较大体积的移植物,可能作为胰岛移植的理想部位。     

Reversal of beta-cell suppression in vitro in pancreatic islets isolated from nonobese diabetic mice during the phase preceding insulin-dependent diabetes mellitus.

Insulin-dependent diabetes mellitus (IDDM) is characterized by a progressive autoimmune destruction of the pancreatic beta-cells. One of the best-suited animal models for IDDM is the nonobese diabetic (NOD) mouse. In this investigation pancreatic islets were isolated from female NOD mice aged 5-7, 8-11, and 12-13 wk and examined immediately (day 0) or after 7 d of culture (day 7). The mice showed a progressive disturbance in glucose tolerance with age, and a correspondingly increased frequency of pancreatic insulitis. Islets isolated from the oldest mice often contained inflammatory cells on day 0, which resulted in an elevated islet DNA content. During culture these islets became depleted of infiltrating cells and the DNA content of the islets decreased on day 7. Islets of the eldest mice failed to respond with insulin secretion to high glucose, whereas a response was observed in the other groups. After culture all groups of islets showed a markedly improved insulin secretion. Islets from the 12-13-wk-old mice displayed a lower glucose oxidation rate at 16.7 mM glucose on day 0 compared with day 7. Islet (pro)insulin and total protein biosynthesis was essentially unaffected. In conclusion, islets obtained from 12-13-wk-old NOD mice exhibit an impaired glucose metabolism, which may explain the suppressed insulin secretion observed immediately after isolation. This inhibition of beta-cell function can be reversed in vitro. Thus, there may be a stage during development of IDDM when beta-cell destruction can be counteracted and beta-cell function restored, provided the immune aggression is arrested.     

糖尿病小鼠理想的胰岛移植部位

背景：胰岛移植到糖尿病小鼠不同部位影响胰岛移植成功率。目的：比较糖尿病小鼠小网膜、肾被膜和腋窝3个部位胰岛移植效果,探索一个更理想的移植部位。方法：应用淋巴细胞分离液分离纯化BALB/c小鼠胰岛;将胰岛移植到造模成功的糖尿病C57BL/6小鼠,按照不同的移植部位小网膜、肾被膜和腋窝进行对比观察。结果与结论：分离纯化后获得高纯度胰岛,每只供体可获得胰岛（102±4）个,并具有良好生物活性;胰岛移植到糖尿病小鼠小网膜、肾被膜和腋窝3个部位后,均能降低血糖至正常范围,移植到小网膜与肾被膜的血糖值差异无显著性意义（P〉0.05）,但均低于腋窝血糖值（P〈0.05）。移植后第7天,苏木精-伊红染色见小网膜部位移植胰岛形态基本完整,肾被膜部位移植胰岛形态不规则,腋窝部位移植物胰岛完全被破坏,伴炎症细胞浸润,小网膜和肾被膜降血糖效果优于腋窝。说明小网膜血供充足容量大,能够接纳较大体积的移植物,可能作为胰岛移植的理想部位。     

Cytotoxic T cells specific for glutamic acid decarboxylase in autoimmune diabetes

Insulin-dependent diabetes mellitus (IDDM) is an autoimmune disease that results in the destruction of the pancreatic islet beta cells. Glutamic acid decarboxylase (GAD) has been recently indicated as a key autoantigen in the induction of IDDM in nonobese diabetic mice. In human diabetes, the mechanism by which the beta cells are destroyed is still unknown. Here we report the first evidence for the presence of GAD-specific cytotoxic T cells in asymptomatic and recent diabetic patients. GAD65 peptides displaying the human histocompatibility leukocyte antigen (HLA)-A*0201 binding motif have been synthesized. One of these peptides, GAD114-123, binds to HLA-A*0201 molecules in an HLA assembly assay. Peripheral blood mononuclear cells from individuals with preclinical IDDM, recent-onset IDDM, and from healthy controls were stimulated in vitro with the selected peptide in the presence of autologous antigen-presenting cells. In three cases (one preclinical IDDM and two recent-onset IDDM), we detected specific killing of autologous antigen-presenting cells when incubated with GAD114-123 peptide or when infected with a recombinant vaccinia virus expressing GAD65. These patients were the only three carrying the HLA-A*0201 allele among the subjects studied. Our finding suggests that GAD- specific cytotoxic T lymphocytes may play a critical role in the initial events of IDDM.     

Aerosol Insulin Induces Regulatory CD8 γδ T Cells That Prevent Murine Insulin-dependent Diabetes

Cellular immune hyporesponsiveness can be induced by the presentation of soluble protein antigens to mucosal surfaces. Most studies of mucosa-mediated tolerance have used the oral route of antigen delivery and few have examined autoantigens in natural models of autoimmune disease. Insulin is an autoantigen in humans and nonobese diabetic (NOD) mice with insulindependent diabetes mellitus (IDDM). When we administered insulin aerosol to NOD mice after the onset of subclinical disease, pancreatic islet pathology and diabetes incidence were both significantly reduced. Insulin-treated mice had increased circulating antibodies to insulin, absent splenocyte proliferation to the major epitope, insulin B chain amino acids 9–23, which was associated with increased IL-4 and particularly IL-10 secretion, and reduced proliferation to glutamic acid decarboxylase, another islet autoantigen. The ability of splenocytes from insulin-treated mice to suppress the adoptive transfer of diabetes to nondiabetic mice by T cells of diabetic mice was shown to be caused by small numbers of CD8 γδ T cells. These findings reveal a novel mechanism for suppressing cell-mediated autoimmune disease. Induction of regulatory CD8 γδ T cells by aerosol insulin is a therapeutic strategy with implications for the prevention of human IDDM.     

骨髓间充质干细胞对大鼠到小鼠胰岛移植的保护作用

目的 探讨同种异基因骨髓间充质干细胞(bone mesenchamal stem cells,BMSC)静脉输注对大鼠到小鼠胰岛移植物的功能保护和小鼠糖尿病状态改善.方法 全骨髓培养法获得C57BL/6小鼠BMSC.不连续梯度离心法分离纯化Sprague-Dawley(SD)大鼠胰岛,将300胰岛当量的胰岛单独或与BM...     

多次小剂量STZ处理建立糖尿病大鼠模型及EGF与Gastrin联合应用对胰岛素分泌的影响

目的通过多次小剂量STZ处理建立糖尿病大鼠模型,观察EGF／Gastrin联合应用对模型大鼠胰岛功能的影响。方法采用35mg·Kg^-1腹腔注射STZ一枸橼酸钠缓冲液,每周1次,连续4周,建立大鼠糖尿病模型。采用生化分析和组织染色的方法观察血糖和胰岛细胞的改变。成模大鼠随机分为三组：Insulin治疗组,EGF／Gastrin联合治疗组及DM对照组。EGF／Gastrin组给予EGF（1μg·Kg^-1）／Gastrin（3μg·Kg^-1）,每日1次皮下注射,连续14日;Insulin组给予长效胰岛素2U／d,连续14日;DM对照组及正常对照组给予枸橼酸钠缓冲液。观察血浆中胰岛素和C肽的改变,评估胰岛细胞功能。结果35只实验组大鼠中有33只血糖值≥11．1mmol·L,占总数的94％。Insulin组大鼠和EGF／Gastrin组大鼠血糖值同DM组相比显著降低。DM组中血清胰岛素及c肽含量显著低于正常对照组（P〈0．05）,而Insulin组及EGF／Gastrin组均显著高于DM组（P〈0．05）。组织学结果观察发现,成模大鼠的胰岛数量明显减少,分布不均匀并出现不同程度的萎缩,出现空泡变性。Insulin免疫组织化学染色结果显示,成模大鼠胰岛内Insulin染色阳性的细胞明显减少;且残存胰岛B细胞Insulin染色强度低于正常对照组,Insulin组及EGF／Gastrin组大鼠胰岛中Insulin表达细胞明显增多,有部分细胞呈强阳性表达。结论EGF和Gastrin联合应用能够促进糖尿病大鼠胰岛功能的恢复。     

Studies of concanavalin A in nonobese diabetic mice. I. Prevention of insulin-dependent diabetes

Concanavalin A (Con A) administered in vivo inhibited the development of insulin-dependent diabetes mellitus (IDDM) in nonobese diabetic mice. By experimental day 310 only one of 10 Con A-treated animals had developed IDDM compared to six of 11 cohort controls receiving buffered saline and 65% of colony controls. Treatment consisted of an initial 70-day course of Con A at a dose of 10 micrograms/g b. wt., i.p. in sterile saline every other day. After two deaths occurred in the Con A group, treatment was stopped at day 70. The remaining animals were given two 1-week booster doses beginning on experimental days 118 and 189. The single animal in the Con A group that eventually developed IDDM at day 293 had not received an injection for 107 days. Histological examination revealed peri-islet lymphocytosis but no islet infiltration in the Con A group. Surviving control animals showed both peri-islet and islet infiltrates. One-week Con A treatment significantly suppressed in vitro responses of spleen cells to Con A and allogeneic lymphocytes. The treatment increased the frequency of "blast-sized" cells in vivo and decreased the CD4+/CD8+ ratio among resting splenocytes. It is concluded that polyclonal T cell activation by Con A provides protection against autoimmune diabetes in nonobese diabetic mice concomitant with phenotypic and morphologic lymphocyte changes.     

Hyperglycemia-induced B cell toxicity. The fate of pancreatic islets transplanted into diabetic mice is dependent on their genetic background.

The role of pancreatic B cell dysfunction in the phase preceding clinical onset of insulin-dependent and non-insulin-dependent diabetes mellitus has been much debated. In this investigation, the impact of a prolonged diabetic environment on pancreatic islet B cells transplanted syngeneically under the kidney capsule of C57BL/6 (B6) and C57BL/Ks (BKs) mice was studied. Alloxan-diabetic mice bearing a subcapsular islet graft insufficient to normalize the blood glucose level were rendered normoglycemic by a second intrasplenic islet graft after various period of hyperglycemia to examine the reversibility of hyperglycemia-induced B cell dysfunction. Using a perfusion technique of the graft-bearing, it was found that both strains of mice exhibited a diminished glucose-induced insulin secretion after 6 wk of hyperglycemia, when compared with normoglycemic mice carrying islet grafts. When normoglycemia was restituted by the splenic graft after 4 or 12 wk, there was a normalization of glucose-stimulated insulin secretion in the renal islet grafts in B6 mice, whereas insulin secretion from the grafted BKs islets remained impaired. Morphometric measurements of the islet grafts demonstrated a 50% reduction in the graft volume in diabetic BKs mice after 12 wk, compared with normoglycemic animals, whereas no such decrease was observed in B6 mice. Islet grafts removed from hyperglycemic mice of both strains exhibited diminished insulin mRNA contents, and in the BKs mice there was also a reduced glucose oxidation rate in the islet grafts in vitro. This metabolic dysfunction can only partly be explained by a reduced graft size. The present findings emphasize the genetic constitution as a decisive factor for the survival and function during a period of sustained stress on a limited B cell mass.     

Glycemic effects of spaghetti and potato consumed as part of mixed meal on IDDM patients

Recently, we demonstrated that spaghetti caused a significantly lower glycemic response in isoinsulinemic insulin-dependent diabetic (IDDM) subjects than an exchangeable amount of potato. The question is, however, whether the difference of the glucose response in IDDM patients is preserved if these carbohydrate-rich foods are taken as part of a mixed meal. To answer this question, we evaluated blood glucose, free-insulin, and glucagon responses to exchangeable amounts of spaghetti and potato when ingested together with bolognese sauce in seven IDDM patients who had attained euglycemia with the artificial pancreas before meal intake. The potato (200 g raw wt) with bolognese sauce (167 g) and spaghetti (50 g raw wt) with bolognese sauce (167 g) had approximately identical caloric content (435 and 447 kcal, respectively), fat (18 g each), protein (23 and 26 g, respectively), and carbohydrate (47 and 48 g, respectively). Blood glucose increment after white spaghetti and bolognese sauce was only approximately 50% of that seen in response to potato and bolognese sauce. Similar constant insulin levels and increments in glucagon were seen. A major determinant of the postmeal glucose rise in IDDM patients seems to be dependent on the kind of carbohydrate in the meal. The approach by which the insulinemia was kept constant by the artificial pancreas seems to be a valuable tool for studying glycemic responses to different meals in IDDM patients who otherwise show great variations in circulating insulin and glucose levels when treated by subcutaneously administered insulin.     

Effects of low-dose cyclosporine prophylaxis in nonobese diabetic mice

Among female nonobese diabetic mice, ketotic insulin-dependent diabetes mellitus (IDDM) develops spontaneously in 80% between 12 and 26 weeks of age. This condition resembles human type I diabetes. IDDM developed in 0 of 11 (0%) mice prophylactically treated with 10 mg of cyclosporine A (CyA) per kg s.c. every 4th day from 8 to 26 weeks of age; 8 of 10 (80%) of sex- and age-matched controls developed IDDM; 2 of 8 (25%) followed up to 5 months beyond the time of drug administration developed IDDM. The distribution of specific radioactivity ([3H]CyA) was used to calculate the concentrations of CyA in serum, blood cells and various organs. Serum values of CyA produced by radioimmunoassay were higher than those estimated by the [3H]CyA method. Pancreata of CyA-treated mice were histologically normal. Pancreata of control mice showed lymphocytic infiltration of the islets of Langerhans. Neither hepatotoxicity nor nephrotoxicity assessed by biochemical and histological data was detectable in CyA-treated mice. The insulin secretory capacity of trypan blue viable functional pancreatic islets isolated post-treatment; was significantly lower in controls than in CyA-treated mice; islet content of insulin was not statistically different between controls and CyA-treated mice. We conclude that low nontoxic doses of CyA abrogate completely the development of diabetes in the female nonobese diabetic mouse and abolish lymphocytic infiltration of the islets of Langerhans against which there is autoimmunity. The effect of CyA persists well past the duration of therapy.