大鼠胰腺γ-氨基丁酸免疫组织化学定位

本文用ABC—GDN免疫组织化学方法,研究了γ-氨基丁酸(Gamma—Aminobutyric Acid,GABA)在大鼠胰腺的定位和分布,并用相邻切片法,观察它与胰岛素的共存关系。结果发现GABA免疫反应阳性细胞主要分布于胰腺内分泌部(胰岛)。在外分泌部亦有少许分布。大部分胰岛细胞呈GABA免疫反应阳性,集中位于胰岛的中央部。相邻连续切片免疫染色证实GABA与胰岛素共存于胰岛B细胞中。外分泌部胰腺GABA免疫反应阳性细胞,呈零散分布于腺泡和导管上皮间。本文为进一步探讨GABA在胰腺的生理作用提供了形态学依据。     

酪氨酸羟化酶在成年大鼠胰腺中的定位

目的:酪氨酸羟化酶(tyrosine hydroxylase,TH)是儿茶酚胺类递质合成的限速梅,儿茶酚胺类递质对胰腺内分泌细胞的功能具有重要的调控作用,本研究拟探讨酪氨酸羟化酶(tyrosine hydroxylase,TH)在成年大鼠整个胰腺的具体定位和表达.方法:取雄性成年大鼠胰腺,冰冻组织切片,应用免疫荧光技术观察酪氨酸羟化酶在整个胰腺中的表达分布情况,并进一步运用免疫荧光双标技术鉴定酪氨酸羟化酶是否与胰岛素、胰高血糖素、生长抑素以及胰多肽分别共定位于β细胞;α细胞;δ细胞及PP细胞,进一步确定合成酪氨酸羟化酶确切的细胞类型.结果:①在胰腺腺泡细胞胞浆中存在酪氨酸羟化酶的阳性表达颗粒.②分布于胰腺外分泌腺的神经纤维和胰岛的神经纤维中都有酪氨酸羟化酶的表达.③酪氨酸羟化酶与胰岛的四种内分泌细胞所合成的肽之间均没有共定位关系.结论:在胰腺,酪氨酸羟化酶只存在于胰腺外分泌腺的腺泡细胞胞浆内以及胰腺中的神经纤维中,而胰岛四种内分泌细胞中没有酪氨酸羟化酶,说明胰腺儿茶酚胺类神经递质一方面由胰腺外分泌部的腺泡细胞合成,另一方面来源于神经末梢的释放,而胰岛细胞不能合成儿茶酚胺类递质;该结果为进一步研究胰腺内、外分泌部之间的关系和儿茶酚胺对胰腺分泌功能的调节提供形态学证据.     

5-羟色胺在豚鼠胰腺分布的免疫组织化学研究

本研究用ABC免疫染色法,结合葡萄糖氧化酶-DAB-硫酸镍铵(Glucose oxidase-DAB-Nickle,GDN)显色技术,在Bouin液固定的常规石蜡切片上,研究了5-羟色胺(5-hydroxytryptamin,5-HT)在豚鼠胰腺内的定位和分布,并用相邻切片免疫双标记,观察了它与胰岛素的共存关系,结果发现,在豚鼠胰腺内,外分泌部均有5-HT免疫反应细胞分布。在胰腺内分泌部(胰岛)5-HT免疫反应细胞分布均匀,大部分胰岛细胞呈阳性5-HT样免疫反应,用相邻薄切片免疫双标记技术证明,胰岛内的5-HT免疫反应细胞主要是B细胞。在胰腺外分泌部,5-HT免疫反应细胞呈单个分散或聚集分布,主要位于腺泡和导管等处,偶见于结缔组织间隔中。本文对研究5-HT在胰腺的生理作用及其机制提供了形态学依据。     

亚东鲑消化系统的形态学和组织学观察

亚东鲑消化系统包括消化道和消化腺。消化道分为明显的食道、胃和肠等。食道粘膜为复层上皮,其中含有杯状细胞和味蕾,胃、肠粘膜为单层柱状上皮,其中散布较多的杯状细胞。消化腺包括肝脏和胰腺,肝小叶分界明显,胰腺外分泌部由腺泡组成,内分泌部即胰岛分散存在于外分泌部之间。     

胰岛素对胰腺外分泌功能的影响

我们用链佐霉素选择性地破坏胰岛Ｂ细胞,研究胰岛素在糖尿病大鼠胰腺外分泌功能变化中的作用。结果表明：糖尿病时,胰淀粉酶含量显著减少,胰淀粉酶ｍＲＮＡ也降低为对照组的３．２±０．５％（Ｐ＜０．０）。体外实验表明,糖尿病大鼠胰腺腺泡上１２５Ｉ－胰岛素的结合明显增多。Ｂｍａｘ由对照组的２．８±１０－９ｍｏｌ／Ｌ增加为３．５±１０－９ｍｏｌ／Ｌ（Ｐ＜０．０１）。腺泡对３Ｈ－葡萄糖的摄取,３Ｈ－亮氨酸的掺入以及腺泡膜Ｎａ＋－Ｋ＋ＡＴＰ酶的活性均比正常组明显降低（Ｐ＜０．０１）。补充胰岛素,可翻转上述变化。从而提示,胰岛素在调节胰腺外分泌功能方面具有重要作用。     

白细胞介素-1受体I型在正常大鼠胰腺的表达

目的研究白细胞介素-1的Ⅰ型受体(IL-1RI)蛋白在正常大鼠胰腺的表达。方法Western blotting和免疫荧光双重染色。结果胰腺组织的Western blotting结果表明,阳性反应条带出现在80 kD处,与IL-1RI分子量一致。免疫荧光双重染色证实,胰岛素(胰岛β细胞的标志物)免疫反应阳性的细胞均为IL-1RI阳性;胰腺外分泌部细胞呈胰岛素免疫反应阴性,但IL-1RI为阳性。结论大鼠胰腺胰岛的β细胞和外分泌部细胞均表达IL-1RI,提示促炎性细胞因子可能对胰腺的内、外分泌功能都有影响。     

哺乳动物胰腺体部胰多肽（PP）免疫反应细胞的比较研究

采用SPA-GDN免疫组化染色技术,对人、大鼠、小鼠、豚鼠、猪、狗和猫等七种哺乳动物胰腺体部胰多肽(PP)免疫反应细胞的分布和形态进行比较研究,结果表明,上述七种动物PP细胞的分布和形态有明显的种间差异。人、大鼠和小鼠PP细胞主要位于胰岛周边部,形成环形结构,少量PP细胞散布在外分泌部的腺泡和导管;而豚鼠、猪和猫的PP细胞则主要分布在外分泌部腺泡和导管上皮间;狗的PP细胞在内、外分泌部均有分布。PP细胞的形态在上述动物间也有明显的差异,这可能与该细胞在不同动物的作用途径及功能不同有关。     

生长抑素可预防链佐霉素诱发的大鼠胰岛 B 细胞分泌功能的损伤

本工作通过测定大鼠血清、胰腺灌流液以及肤腺组织中胰岛素含量,观察生长抑素(SS)对链佐霉素(STZ)诱发的实验性糖尿病的作用。结果如下:皮下注射生理盐水后10min,再向腹腔注射链佐霉素(35mg/kg),24h 后大鼠血清胰岛素浓度明显降低。胰腺组织匀浆中的胰岛素含量也明显减少。如若在注射链佐霉素前10min 皮下注射生长抑素,则可有效地防止上述两项指标的改变,(NS STZ)和(SS STZ)两组之间具有显著差异。单独注射生长抑素,24h 后血清胰岛素及胰腺组织中胰岛素含量与正常对照无明显差异。用分离的大鼠胰腺作体外灌流,观察到:NS STZ 组大鼠灌流胰腺对19.7mmol/L 的高浓度葡萄糖刺激无胰岛素释放反应,而 SS STZ 组大鼠的胰腺对高浓度葡萄糖有反应性,刺激后出现胰岛素分泌峰。上述结果表明,SS(30μg/kg)预防性注射可以防止 STZ 引起的胰岛 B 细胞分泌功能的障碍。     

1型糖尿病小鼠模型中MZB和FoB细胞的检测

目的:探究脾脏边缘区B细胞(marginal zone B cell,MZB)和滤泡状B细胞(folicular B cell,FoB)在链脲佐菌素(streptozocin,STZ)诱导的1型糖尿病小鼠模型中的频率变化。方法:以C57BL/6小鼠为研究模型,腹腔注射STZ 55 mg/kg,连续注射5天,建立1型糖尿病模小鼠模型。选取随机血糖水平≥200 mg/dL(11.1 mmol/L)的小鼠视为造模成功。期间观察并记录小鼠摄食、饮水情况,监测小鼠体重、空腹血糖情况。造模第4周处死小鼠,随后测定小鼠的糖化血红蛋白(glycated hemoglobin, HbA1c)、谷氨酸脱羧酶抗体(GAD65)、胰岛素自身抗体(IAA)水平。通过对各组小鼠胰腺进行苏木精-伊红(hematoxylin-eosin, HE)染色、免疫组化(immunohistochemistry,IHC)观察胰岛形态变化及胰岛素含量。通过流式细胞术,比较各组小鼠脾脏中MZB和FoB细胞的频数和表型。结果:与正常对照组小鼠比较,STZ糖尿病模型组小鼠摄食量、饮水量明显增加,体重减轻,随机血糖显著升高,同时HbA1c水平明显增加(P0.0001),模型组小鼠血浆GAD65和IAA水平也明显升高。HE、IHC结果显示,与正常对照小鼠比较,STZ糖尿病小鼠胰岛萎缩、呈不规则;胰岛素颗粒数减少。与正常对照组小鼠相比,模型组小鼠脾脏MZB细胞频数增加,差异有统计学意义(P0.05);与正常对照组小鼠相比,模型组小鼠脾脏FoB细胞频数无统计学差异。结论:STZ诱导的1型糖尿病小鼠脾脏中MZB细胞频数升高,FoB细胞频数变化无统计学差异。这些B淋巴细胞亚群频率失衡可能与1型糖尿病的发生有关。     

神经元限制性沉默因子与胰岛素在成年小鼠胰腺中的表达

目的:观察神经元限制性沉默因子(NRSF)在正常成年小鼠胰腺组织中的表达情况。方法:以6～8周BALB/c小鼠胰腺为实验材料,制备冰冻切片,与地高辛标记的NRSF cDNA探针进行原位杂交,观察mRNA表达,并结合免疫组织化学方法检测NRSF和胰岛素的表达。结果:原位杂交显示,NRSF mRNA仅表达于胰腺组织外分泌部腺泡腺细胞中,胞浆呈蓝紫色,与免疫荧光组织化学检测NRSF蛋白表达的部位一致,而胰岛细胞中无NRSF mRNA及蛋白的表达。免疫酶组织化学染色显示,胰岛大部分细胞中表达胰岛素,胞浆染成黄棕色,而腺泡腺细胞则不表达胰岛素。结论:NRSF与胰岛素不存在共定位关系,即成年小鼠胰岛细胞不表达NRSF,而表达胰岛素。提示NRSF蛋白表达的消失可能是建立完全分化成熟、具有完好分泌反应的胰岛细胞所必需的。     

Effects of cadmium exposure on morphological aspects of pancreas,weights of fetus and placenta in streptozotocin-induced diabetic pregnant rats

This study was designed to evaluate the effects of Cd exposure on morphological aspects of β-cell and weights of fetus and placenta in streptozotocin (STZ)-induced diabetic pregnant rats. Ninety-nine virgin female Wistar rats (200–220 g) were mated with 33 males for at least 12 h. From the onset of pregnancy, the rats were divided into four experimental groups (control, Cd treated, STZ treated, and Cd+STZ treated). The Cd-treated group was injected subcutaneously daily with CdCl₂ dissolved in isotonic NaCl, starting at the onset of pregnancy throughout the experiment. Diabetes was induced on the 13th d of pregnancy by a single intraperitoneal injection of STZ in STZ-treated group. In addition to the daily injection of Cd, a single intraperitoneal injection of STZ was also given on the 13th d of pregnancy in the Cd+STZ-treated group. The rats received the last injection 24 h before being sacrificed and 10 randomly selected rats in each group were sacrificed on the 15th and 20th d of pregnancy. Blood samples were taken for the determination of the serum glucose and insulin levels. Maternal pancreases, fetuses, and placentas of sacrificed rats in all groups were harvested (fetal pancreas was also harvested only on the 20th d of pregnancy) for morphological and immunohistochemical examinations. Cd exposure alone caused a degeneration, necrosis, and weak degranulation, but Cd exposure with STZ caused a severe degeneration, necrosis, and degranulation in the β-cells of the pancreatic islets. No morphological or immunohistochemical differences were found in β-cells of fetal pancreatic islets of control or other treatment groups. Cd exposure alone also decreased the fetal and placental weights. The administration of STZ alone, on the other hand, increased the placental weight. Cd, STZ, and Cd+STZ administration increased the glucose and decreased the insulin level. The increase in glucose and decrease in insulin levels were higher when Cd and STZ were given together. All of these changes were more severe on the 20th d than those on the 15th d of the pregnancy. It is concluded that Cd exposure during pregnancy may reduce the birth and placental weights and produce necrosis, degeneration, and degranulation in β-cells of pancreatic islets, causing an increase in the serum glucose level. These changes might be severe in diabetic pregnant mothers.     

绍兴麻鸭胰腺D细胞年龄变化的显微图像分析

用免疫组织化学ＡＢＣ法,研究不同生长期中,绍兴麻鸭胰腺脾叶内Ｄ细胞的形态分布;用显微图像分析系统测定Ｄ细胞的积分光密度值,并求各时期Ｄ细胞的平均总积分光密度值,再作统计学分析。结果表明：Ｄ细胞多呈三角或多面形,具多种形态的胞质突起。常成群散在分布于胰岛内,少数零散位于胰腺中。Ｄ细胞积分光密度值的年龄变化是７—４２日龄为生长发育峰期,以后呈缓慢下降趋势,其中７－１４日龄为增长高峰期（呈现极显著差异）。本文显示了胰腺Ｄ细胞在生长发育期的变化规律,并讨论了该变化规律与绍兴麻鸭胃腺Ｄ细胞及胰岛Ｂ细胞变化规律间的关系。为胃肠胰内分泌系统的发育提供动态变化的基础资料。     

Morphological changes in the endocrine pancreas of mice after treatment with streptozotocin combined with cyclophosphamide and neurotropin.

The effect of neurotropin (NSP) in combination with streptozotocin (STZ) and cyclophosphamide (CY) on blood glucose and pancreatic histopathology on day 7 and day 14 after the initiation of the treatment was studied in C57Bl/6 male mice. STZ (40 mg/kg) and NSP (1 mg/kg) were applied intraperitoneally on five consecutive days and CY (150 mg/kg)--twice on day 1 and day 3. In single B cells dilatation of the endoplasmic reticulum was found. On day 7 in proximity to some endocrine cells in the mice treated with STZ, STZ + CY + NSP and STZ + CY macrophages were observed. On day 14 lymphocytic infiltration of the islets was demonstrated only in the groups of mice injected with STZ, STZ + CY while in the group treated with the combination STZ + CY + NSP no infiltration was seen. All experimental groups showed no biochemical evidence for hyperglycemia probably due to the mild destruction of a small number of B cells. The results indicate that NSP might possess a restorative action on insulitis induced by multiple low dose streptozotocin administration in mice.     

Pancreatic and hepatic glycogen content in normoglycemic and hyperglycemic rats

As judged from morphological criteria, glycogen accumulates to a larger extent in insulin-producing B-cells than in acinar cells of the pancreas in situations of sustained hyperglycemia. In the present study, the glycogen content of the pancreatic gland and liver was measured in either euglycemic or glucose-infused hyperglycemic control rats, as well as in streptozotocin-induced diabetic rats. Whilst the glycogen content of the pancreas was significantly higher in STZ rats than in control euglycemic rats, it was further enhanced in glucose-infused control rats, despite the fact that the latter animals were not more severely hyperglycemic and for a shorter time than STZ rats. From these measurements, it was estimated that, relative to wet weight, the glycogen content was, under the present experimental conditions, about 75 times higher in insulin-producing than other pancreatic cells. Moreover, it is proposed that the intravenous administration of glucagon may help in distinguishing between the glycogen present in the endocrine and exocrine moieties of the pancreatic gland, this hormone being apparently unable to provoke glycogenolysis in the exocrine pancreas, at variance with the situation prevailing in isolated pancreatic islets.     

胰岛淀粉样多肽在豚鼠胰腺分布的免疫组织化学研究

本文用免疫组织化学ＡＢＣ法,研究了胰岛淀粉样多肽（Ｉｓｌｅｔａｍｙｌｏｉｄｐｏｌｙｐｅｐｔｉｄｅ,ＩＡＰＰ或称Ａｍｙｌｉｎ）在豚鼠胰脏的分布,并用邻片免疫组织化学双标记法,观察了ＩＡＰＰ与胰岛素（Ｉｎｓｕｌｉｎ,ＩＮＳ）、生长抑素（ＳｏｍａｔｏｓｔａｔｉｎＳＳ）的共存关系。结果显示,豚鼠胰岛内绝大多数细胞都呈ＩＡＰＰ阳性免疫反应,在胰外分泌部的腺泡和导管内也散在分布有ＩＡＰＰ免疫反应阳性细胞。多数ＩＡＰＰ免疫反应阳性的细胞都显示ＩＮＳ免疫反应阳性,胰岛内少数ＩＡＰＰ阳性细胞也呈ＳＳ免疫反应阳性。说明ＩＡＰＰ主要分布在豚鼠的胰岛内．但也少量存在于外分泌部。ＩＡＰＰ主要和ＩＮＳ共存于Ｂ细胞内。但也和ＳＳ共存于Ｄ细胞内,提示ＩＡＰＰ可能通过自分泌途径调节ＩＮＳ和ＳＳ的分泌。     

Scoparia dulcis, a traditional antidiabetic plant, protects against streptozotocin induced oxidative stress and apoptosis in vitro and in vivo

Oxidative stress is implicated in the pathogenesis of diabetic complications. The experiments were performed on normal and experimental male Wistar rats treated with Scoparia dulcis plant extract (SPEt). The effect of SPEt was tested on streptozotocin (STZ) treated Rat insulinoma cell lines (RINm5F cells) and isolated islets in vitro. Administration of an aqueous extract of Scoparia dulcis by intragastric intubation (po) at a dose of 200 mg/kg body weight significantly decreased the blood glucose and lipid peroxidative marker thiobarbituric acid reactive substances (TBARS) with significant increase in the activities of plasma insulin, pancreatic superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH) in streptozotocin diabetic rats at the end of 15 days treatment. Streptozotocin at a dose of 10 mug/mL evoked 6-fold stimulation of insulin secretion from isolated islets indicating its insulin secretagogue activity. The extract markedly reduced the STZ-induced lipidperoxidation in RINm5F cells. Further, SPEt protected STZ-mediated cytotoxicity and nitric oxide (NO) production in RINm5F cells. Treatment of RINm5F cells with 5 mM STZ and 10 mug of SPEt completely abrogated apoptosis induced by STZ, suggesting the involvement of oxidative stress. Flow cytometric assessment on the level of intracellular peroxides using fluorescent probe 2'7'-dichlorofluorescein diacetate (DCF-DA) confirmed that STZ (46%) induced an intracellular oxidative stress in RINm5F cells, which was suppressed by SPEt (21%). In addition, SPEt also reduced (33%) the STZ-induced apoptosis (72%) in RINm5F cells indicating the mode of protection of SPEt on RIN m5Fcells, islets, and pancreatic beta-cell mass (histopathological observations). Present study thus confirms antihyperglycemic effect of SPEt and also demonstrated the consistently strong antioxidant properties of Scoparia dulcis used in the traditional medicine.     

Protective effect of rat pancreatic progenitors cells expressing Pdx1 and nestin on islets survival and function in vitro and in vivo

To maintain islets survival and function is critical in successful pancreatic transplantation. Pancreatic progenitors cells (PPCs) with lineage potentials, giving rise to exocrine, endocrine, and duct cells, reside in developing and adult pancreas. As tissue-specific stem cells, they can produce pancreatic tissue-specific matrix factors to promote islets survival and function. The aim of our research was to investigate the protective effect of rat pancreatic?Cduodenal homeobox 1 (Pdx1)⁺/nestin⁺ PPCs on islets. In vitro, co-culturing islets with Pdx1⁺/nestin⁺ PPCs prolonged the former survival from 7 to 14?days. Furthermore, with high glucose (300.8?mg/dl) stimuli, the yield of insulin in co-cultures was significantly higher than that in control group (single islets group). In vivo, co-transplanting islets and Pdx1⁺/nestin⁺ PPCs for 3?days, the blood glucose of diabetic rat was significantly decreased to normal level and sustained for 2?weeks. Without Pdx1⁺/nestin⁺ PPCs in islets transplantation, hyperglycemia was reversed at day 7 and recovered at day 15. Pathology analysis showed that islets had remnants in co-transplantation at day 21, as complete graft rejection in alone islets transplantation. Our study showed that Pdx1⁺/nestin⁺ PPCs displayed the ability of preserving islets viability and function in vitro and prolonging their survival in vivo.     

锌和维生素E对Ⅰ型糖尿病大鼠心肌的保护作用

目的探讨锌（Zn）和维生素E（VE）对糖尿病大鼠心肌细胞保护作用的机制。方法按体重将大鼠随机分为正常对照组（10只）和实验组（40只）,实验组动物采用腹腔注射链脲左菌素（streptozotocin,STZ）,60mg/kg一次注射,制备糖尿病大鼠模型。将40只按血糖值参考体重分为4组：糖尿病对照组,糖尿病补锌组,糖尿病补VE组,糖尿病补Zn＋VE组。6周后将各组大鼠处死,切取心室肌组织,进行免疫组织化学染色,观察各组心肌组织NF-κB和i NOS的表达水平,利用HPIAS-2000图像分析系统测定核转录因子（nuclear factor-kappa B,NF-κB）和诱导型一氧化氮合酶（i NOS）在以上各组中表达的平均光密度和平均阳性面积率。结果正常对照组心肌细胞内NF-κB和i NOS呈阴性表达,糖尿病对照组心肌细胞内NF-κB和i NOS呈阳性表达;糖尿病补锌组和糖尿病补VE组心肌细胞内NF-κB和i NOS呈弱阳性表达;糖尿病补Zn＋VE组心肌细胞内NF-κB和i NOS呈阴性表达。图像分析结果显示：糖尿病补Zn＋VE组与糖尿病对照组、糖尿病补锌组及糖尿病补VE组之间NF-κB和i NOS的平均光密度及阳性面积率的差异有显著性意义（P〈0.05）;糖尿病补Zn＋VE组与正常组之间NF-κB和i NOS的平均光密度及阳性面积率的差异无显著性意义（P〉005）。结论Zn和VE联合使用可降低糖尿病大鼠心肌组织中NF-κB和i NOS的活性,对糖尿病大鼠心肌细胞具有保护作用。     

Insulin secretion and islet endocrine cell content at onset and during the early stages of diabetes in the BB rat: effect of the level of glycemic control.

Although it is agreed that autoimmune destruction of pancreatic islets in diabetic BB rats is rapid, reports of endocrine cell content of islets from BB diabetic rats at the time of onset of diabetes vary considerably. Because of the rapid onset of the disease (hours) and the attendant changes in islet morphology and insulin secretion, it was the aim of this study to compare islet beta-cell numbers to other islet endocrine cells as close to the time of onset of hyperglycemia as possible (within 12 h). As it has been reported that hyperglycemia renders the beta cell insensitive to glucose, the early effects of different levels of insulin therapy (well-controlled vs. poorly controlled glycemia) on islet morphology and insulin secretion were examined. When measured within 12 h of onset, insulin content of BB diabetic islets, measured by morphometric analysis or pancreatic extraction, was 60% of insulin content of control islets. Despite significant amounts of insulin remaining in the pancreas, 1-day diabetic rats exhibited fasting hyperglycemia and were glucose intolerant. The insulin response from the isolated perfused pancreas to glucose and the glucose-dependent insulinotropic hormone, gastric inhibitory polypeptide (GIP), was reduced by 95%. Islet content of other endocrine peptides, glucagon, somatostatin, and pancreatic polypeptide, was normal at onset and at 2 weeks post onset. A group of diabetic animals, maintained in a hyperglycemic state for 7 days with low doses of insulin, were compared with a group kept normoglycemic by appropriate insulin therapy. No insulin could be detected in islets of poorly controlled diabetics, while well-controlled animals had 30% of the normal islet insulin content.(ABSTRACT TRUNCATED AT 250 WORDS)