白细胞介素-1对大鼠离体胰岛B细胞分泌功能的影响

目的 :观察白细胞介素 1(IL 1)对大鼠胰岛B细胞分泌功能的影响并探讨其机制。方法 :采用胰岛细胞培养的方法 ,观察IL 1对胰岛素分泌和MTT还原的影响 ;通过分子杂交检测c fosmRNA并分析蛋白质合成的变化。结果 :IL 1作用后胰岛素分泌和MTT还原量明显减少 ,且有时间依赖性 ;IL 1诱导c fosmRNA ,从而使细胞蛋白质表达发生变化。结论 :IL 1可能通过改变胰岛细胞内基因表达 ,抑制细胞代谢 ,从而使胰岛素分泌减少     

Pancreatic islet blood flow and its measurement

Pancreatic islets are richly vascularized, and islet blood vessels are uniquely adapted to maintain and support the internal milieu of the islets favoring normal endocrine function. Islet blood flow is normally very high compared with that to the exocrine pancreas and is autonomously regulated through complex interactions between the nervous system, metabolites from insulin secreting β-cells, endothelium-derived mediators, and hormones. The islet blood flow is normally coupled to the needs for insulin release and is usually disturbed during glucose intolerance and overt diabetes. The present review provides a brief background on islet vascular function and especially focuses on available techniques to measure islet blood perfusion. The gold standard for islet blood flow measurements in experimental animals is the microsphere technique, and its advantages and disadvantages will be discussed. In humans there are still no methods to measure islet blood flow selectively, but new developments in radiological techniques hold great hopes for the future.     

血糖波动对糖尿病大鼠胰岛素释放和胰岛素敏感性的影响

目的:观察血糖波动对糖尿病大鼠胰岛素释放和胰岛素敏感性的影响.方法:GK大鼠22只,随机分为糖尿病高血糖组、糖尿病血糖波动组,Wistar大鼠11只作为正常对照组,进行葡萄糖耐量实验(IPGTT)及在体胰岛分离后体外葡萄糖刺激下胰岛素释放实验(GSIS),并检测胰岛素相关基因的表达,以了解β细胞的胰岛素释放功能,进行胰岛素耐量试验以检测胰岛素敏感性的情况.结果:实验6周后血糖波动组和持续高血糖组体重无统计学差异.血糖波动组空腹血糖,糖负荷后15、30、60、120 min血糖,糖曲线下面积(AUCG)均高于持续高血糖组(P均<0.05).在体胰岛分离后体外葡萄糖刺激下胰岛素释放指数明显低于持续高血糖组(P均<0.05).血糖波动组胰岛素基因ins-1、ins-2和pdx-1表达及胰岛素敏感性较持续高血糖组显著降低(P均<0.05).结论:血糖波动使GK大鼠胰岛素释放功能降低并且胰岛素相关基因表达减少可能是胰岛素释放减少的原因之一,血糖波动使胰岛素敏感性降低.     

高浓度芬太尼抑制体外培养大鼠胰岛葡萄糖刺激胰岛素分泌

目的研究高浓度芬太尼对大鼠胰岛的损伤作用。方法通过用胶原酶V液灌注分离成年SD大鼠胰岛,不连续密度梯度离心法纯化胰岛。然后将胰岛分为空白对照组和处理组,处理组与20ng／ml的芬太尼在静态条件下共同培养24h和后,检测低高浓度葡萄糖（2．8和16．7mmol／L）刺激胰岛素释放试验,细胞内cAMP及蛋白含量,电子显微镜检测胰岛细胞。结果高浓度的芬太尼明显抑制大鼠胰岛的葡萄糖刺激胰岛素释放量,及细胞内cAMP的含量,电子显微镜检测显示高浓度芬太尼对大鼠胰岛具有损伤作用。结论高浓度芬太尼抑制体外培养大鼠胰岛素的分泌,并且对鼠胰岛细胞具有一定的损伤作用。     

IL-6促进胰岛细胞胰岛素分泌在PCOS发病机制中的作用

目的 探讨IL-6在多囊卵巢综合征(polycystic ovary syndrome, PCOS)高胰岛素血症和胰岛素抵抗中的作用。方法 在体外培养的大鼠胰岛细胞培养液中加入10、100和1000pg/ml IL-6,于培养24、48、72h后,采用放射免疫法检测IL-6对胰岛细胞胰岛素分泌的影响。结果 培育48h时,1000pg/ml IL-6板孔中的胰岛素浓度高于对照组,差异有统计学意义(P＜0.05);培育72h时,100、1000pg/ml IL-6板孔中的胰岛素浓度均高于对照组,差异有统计学意义(P＜0.05)。结论 IL-6在体外具有刺激胰岛细胞分泌胰岛素的作用,这可能与PCOS患者常出现高胰岛素血症、胰岛素抵抗现象有关。     

RNA interference targeting mu-opioid receptors reverses the inhibition of fentanyl on glucose-evoked insulin release of rat islets

Background Mu opioid receptor plays an important role in many physiological functions. Fentanyl is a widely used opioid receptor agonist for analgesia. This study was conducted to test the role of mu-opioid receptor on insulin release by determining whether fentanyl affected insulin release from freshly isolated rat pancreatic islets and if small interfering RNAs （siRNA） targeting mu-opioid receptor in the islets could knock down mu-opioid receptor expression.Methods Islets were isolated from ripe SD rats＇ pancreas by common bile duct intraductal collagenase V digestion and purified by discontinuous Ficoll density gradient centrifugation. The siRNA knock-down of mu-opioid receptor mRNA and protein in islet cells was analyzed by semi-quantitative real time-PCR and Western blotting. After siRNA-transfection for 48 hours, the islets were co-cultured with fentanyl as follows： 0 ng/ml, 3 ng/ml and 30 ng/ml for 48 hours. Then glucose-evoked insulin release was performed. As a control, the insulin release was also analyzed in islets without siRNA-trasfection after being co-cultured with fentanyl for 48 hours.Results After 48 hours of transfections, specific siRNA targeting of mu-opioid receptors produced significant reduction of mu-opioid receptor mRNA and protein （P ＜0.01）. Fentanyl significantly inhibited glucose-evoked insulin release in islets in a concentration dependent manner （P ＜0.01）. But after siRNA-transfection for 48 hours, the inhibition on glucose-evoked insulin reiease was reversed （P ＜0.01）.Conclusions RNA interference specifically reduces mu-opioid receptor mRNA and protein expression, leading to reversal of the fentanyl-induced inhibition on glucose-evoked insulin release of rat islets. The activation of opioid receptor induced by fentanyl functions to inhibit insulin release. The use of RNAi presents a promising tool for future research in diabetic mechanisms and a novel therapy for diabetes.     

胃旁路术对血糖及胰岛细胞的影响

目的研究胃旁路术（gastricbypasssurgery,GBP）对糖尿病大鼠血糖的控制效果及对胰岛细胞的影响。方法采用链脲佐菌素建立糖尿病SD大鼠模型20只,随机数表法分为糖尿病手术组（DO组）和糖尿病对照组（DC组）,另取20只非糖尿病大鼠随机数表法分为正常对照组（NC组）和正常手术组（NO组）。DO组和NO组大鼠行GBP,DC组和NC组大鼠行假手术,分别检测各组大鼠术前、术后72h、1、4和8周空腹血糖水平。术后8周,取胰腺组织行HE染色和免疫荧光,观察组织学变化。结果术前DO组与DC组及NC组与NO组大鼠空腹血糖之间比较差异均无统计学意义（P〉0．05）。DO组大鼠术后空腹血糖进行性下降（P〈0．05）。DC组大鼠术前及术后各时相的血糖差异无统计学意义（P〉0．05）;NO组和NC组大鼠组内不同时相及组间相同时相空腹血糖之间比较差异均无统计学意义（P〉0．05）。镜下HE染色：手术组大鼠胰腺内出现新生的小胰岛,胰岛数目增加,这些新生的胰岛体积较小,大部分出现在胰管周围且结构接近正常胰岛;免疫荧光染色显示：胰岛数目增加,胰岛素免疫荧光发现较多孤立的及由两三个胰岛素阳性细胞组成的小胰岛。胰岛素和胰高血糖素免疫荧光双标发现在部分胰岛内存在胰岛素和胰高血糖素双阳性（INS^＋／GLU^＋）的细胞。结论GBP对2型糖尿病大鼠具有明显的降糖作用,胰岛再生在其中起着重要作用,但对正常大鼠血糖无影响。     

胰岛功能指标在胰岛素瘤与胰岛素自身免疫综合征中比较分析

目的:比较分析不同胰岛功能指标在胰岛素瘤和胰岛素自身免疫综合征（IAS）中的诊断价值。方法:回顾性分析我院2005年1月-2019年3月明确诊断的胰岛素瘤和IAS病例，比较分析胰岛素（INS）、胰岛素释放指数（IRI）、胰岛素释放修正指数（修正IRI）、C肽、C肽释放指数（CPI）、C肽释放修正指数（修正CPI）、胰岛素/C肽在两组诊断价值以及低血糖发作时胰岛素与C肽相关性研究。结果:胰岛素瘤组24例，IAS组9例，各指标在胰岛素瘤组和IAS组中均有差异。IAS组INS、IRI、修正IRI、C肽、CPI、修正CPI、胰岛素/C肽都高于胰岛素瘤组（均P<0.01）。低血糖发作时，IAS组INS与C肽之间相关性不显著，在胰岛素瘤组中相关性为0.695（P<0.01）。结论:利用各胰岛功能指标在胰岛素瘤和IAS中的差异表达，有助于提高胰岛素瘤和IAS在临床中的鉴别诊断。     

低氘白酒对糖尿病大鼠糖代谢和胰岛细胞及其功能的影响

目的 探讨低氘白酒干预对糖尿病大鼠空腹血糖水平和胰岛细胞及其功能的影响。方法 一次性腹腔注射链脲佐菌素（STZ）诱导建立糖尿病Wistar大鼠模型,根据干预方式的不同将糖尿病大鼠分为模型组（生理盐水灌胃,饮用普通水）、低氘水组（低氘水灌胃,饮用低氘水）、普通白酒组\[1个单位（低量）或6个单位（高量）白酒+蒸馏水灌胃,饮用普通水）、低氘白酒组(低量或高量白酒+低氘水灌胃,饮用低氘水）,每组10只;以10只未造模大鼠作为正常对照组（生理盐水灌胃,饮用普通水）;各组大鼠每日灌胃液体量均为0.01 mL/g。于干预后4周末,各组大鼠经眼眶静脉采集血样后颈椎脱臼处死,摘除并制备胰腺组织标本。葡萄糖氧化酶法和放射免疫分析法分别测定空腹血糖和胰岛素水平;胰腺组织标本HE染色观察各组大鼠胰岛组织病理学改变。结果 空腹血糖水平,普通白酒高量组>模型组＞普通白酒低量组>低氘白酒高量组>低氘水组>低氘白酒低量组,其中低氘水组和低氘白酒低量组与其他各组比较差异均有统计学意义(P<0.05)。空腹胰岛素水平,低氘白酒低量组>低氘白酒高量组>普通白酒低量组>低氘水组>普通白酒高量组>模型组;除普通白酒高量组外,其余各组均显著高于模型组（P<0.05）。胰岛组织学观察显示,与正常对照组比较,模型组和普通白酒组大鼠的胰岛细胞数量减少、体积增大、胞质呈空泡状,细胞排列紊乱,低氘水组和低氘白酒组胰岛细胞受损程度较轻。结论 低氘白酒干预能显著降低糖尿病大鼠的空腹血糖水平,提高血浆胰岛素水平;减轻因过量饮酒导致的胰岛细胞损伤。     

低氘白酒对糖尿病大鼠糖代谢和胰岛细胞及其功能的影响

目的 探讨低氘白酒干预对糖尿病大鼠空腹血糖水平和胰岛细胞及其功能的影响.方法 一次性腹腔注射链脲佐菌素（STZ）诱导建立糖尿病Wistar大鼠模型,根据干预方式的不同将糖尿病大鼠分为模型组（生理盐水灌胃,饮用普通水）、低氘水组（低氘水灌胃,饮用低氘水）、普通白酒组[1个单位（低量）或6个单位（高量）白酒＋蒸馏水灌胃,饮用普通水）、低氘白酒组（低量或高量白酒＋低氘水灌胃,饮用低氘水）,每组10只;以10只未造模大鼠作为正常对照组（生理盐水灌胃,饮用普通水）;各组大鼠每日灌胃液体量均为0.01 mL/g.于干预后4周末,各组大鼠经眼眶静脉采集血样后颈椎脱臼处死,摘除并制备胰腺组织标本.葡萄糖氧化酶法和放射免疫分析法分别测定空腹血糖和胰岛素水平;胰腺组织标本HE染色观察各组大鼠胰岛组织病理学改变.结果 空腹血糖水平,普通白酒高量组〉模型组＞普通白酒低量组〉低氘白酒高量组〉低氘水组〉低氘白酒低量组,其中低氘水组和低氘白酒低量组与其他各组比较差异均有统计学意义（P〈0.05）.空腹胰岛素水平,低氘白酒低量组〉低氘白酒高量组〉普通白酒低量组〉低氘水组〉普通白酒高量组〉模型组;除普通白酒高量组外,其余各组均显著高于模型组（P〈0.05）.胰岛组织学观察显示,与正常对照组比较,模型组和普通白酒组大鼠的胰岛细胞数量减少、体积增大、胞质呈空泡状,细胞排列紊乱,低氘水组和低氘白酒组胰岛细胞受损程度较轻.结论 低氘白酒干预能显著降低糖尿病大鼠的空腹血糖水平,提高血浆胰岛素水平;减轻因过量饮酒导致的胰岛细胞损伤.     

Functional stimulation of graft nerves has minor effects on insulin release from transplanted rat pancreatic islets

Abstract

Introduction. Morphological evidence for reinnervation of pancreatic islet grafts is plentiful. However, to what extent intra-graft nerves influence the endocrine functions of the islet transplant is largely unknown. We therefore aimed to directly stimulate nerves leading to islet grafts with electrodes and measure insulin secretion in response to this.

Methods. We implanted syngeneic islets under the renal capsule of rats, and examined them 1 or 7–9 months later. In anesthetized rats blood samples were collected from the renal vein and femoral artery, respectively, during electrode stimulation of the nerves leading to the islet grafts.

Results. As expected, nerve stimulation decreased renal blood flow. However, serum insulin concentrations in samples derived from the renal vein or femoral artery changed in concert with one another, both during normoglycemia and acute hyperglycemia.

Conclusion. Reinnervation which occurs after islet transplantation under the renal capsule has minor effects on graft endocrine function.     

甘精胰岛素联合阿卡波糖对老年糖尿病的疗效和胰岛功能的影响

目的 探讨甘精胰岛素(GL)或中性鱼精蛋白锌胰岛素(NPH)联合阿卡波糖对老年糖尿病的疗效和治疗前后对胰岛功能的影响.方法 对42例初诊老年糖尿病患者分别于睡前注射GL(23例)或NPH(19例),口服阿卡波糖,观察8周前后空腹血糖、餐后2h血糖、糖化血红蛋白、空腹C肽和餐后C肽的变化.结果 二组均有明显的降血糖作用,但GL组发生的低血糖事件更少,C肽水平明显提高.结论 应用GL和NPH睡前注射均对老年糖尿病的疗效较好,但GL的低血糖发生率低,且可改善胰岛功能.     

Effects of L-lysine monohydrochloride on insulin and blood glucose levels in spinal cord injured rats

Background Hyperglycemia in brain and spinal cord could aggravate neurologic impairment. Recent studies showed that L-lysine monohydrochlonde （LMH） could increase the insulin secretion and regulate the blood glucose level. The aim of the present study was to investigate the effects of LMH on pancreatic islet B cells, the levels of endogenous insulin and blood glucose in spinal cord injured rats.Methods Forty male Wistar rats were divided into four groups, namely, normal control group, model group, high-dose LMH group （621.5 mg/kg equal to LMH 1/8 LD50）, and low-dose LMH group （310.8 mg/kg equal to LMH 1/16 LD50）. The model of spinal cord injured rat was established by hemi-transection at the lower right thoracic spinal cord. LMH was administered via intraperitoneal injection once spinal cord injury was produced in rats. All rats were sacrificed 48 hours after spinal cord injured. The effects of LMH on pancreatic islet B cells, the content of endogenous insulin, end the level of blood glucose were observed with immunohistochemical method, radioimmunoassay method, end biochemical analyzer, respectively. Results The insulin immunohistochemical intensities of islet B cells were significantly weaker in model group then those in normal control group （P 〈0.01）. The levels of endogenous insulin were significantly lower and the blood glucose levels were significantly higher in model group than those in normal control group （P 〈0.01）. The insulin immunohistochemical intensities of islet B cells were significantly stronger in high-dose LMH group then those in model group （P〈0.05）. In addition, we found that the levels of endogenous insulin were significantly higher and the blood glucose levels were significantly lower in high-dose LMH group then those in model group （P 〈0.05）. There were no significant differences in the insulin immunohistochemical intensities of islet B cells, the levels of endogenous insulin and the blood glucose between low-dose LMH group and model group （P 〉0.05）. Conclusion LMH, but dose-dependent, might participate in the regulation of pancreatic islet B cells, and then reduce the blood glucose levels in the spinal cord injured rats.     

大鼠妊娠期胰岛形态及β细胞增殖能力的变化

目的:探讨大鼠妊娠不同阶段胰岛形态及β细胞增殖的变化.方法:采用5-溴尿脱氧嘧啶核苷(BrdU)及抗胰岛素抗体免疫组化双染法,通过形态学及量化分析,研究大鼠妊娠10.5、12.5、14.5、18.5和20.5天时胰岛形态的改变及β细胞的增殖率的改变.结果:与正常对照组相比,大鼠妊娠12.5天时胰岛素染色阳性区域平均光密度、胰岛素相对浓度(IRC)、胰岛素阳性表达细胞密度(PCD)以及胰岛β细胞增殖指数(PI)均明显增高,并于孕14.5天到达高峰,而后逐渐下降至对照组水平.此外,大鼠妊娠14.5天至20.5天时胰岛素阳性表达细胞面积亦明显高于正常水平.结论:大鼠妊娠期胰岛β细胞的增殖能力和胰岛素表达,均从孕12.5天开始发生改变,孕14.5天变化最为显著,并持续至孕晚期(孕20.5天).     

六甲氧苄嗪对大鼠器官局部血流量的影响

作对＾５１Ｃｒ标记的蛙红细胞作为放射活性生物微球，测定六甲氧苄嗪（ＨＭＺ）对正常麻醉大鼠各器官局部血流的影响。结果表明，ＨＭＺ０．５和４．０ｍｇ／ｋｇ能明显增加心脏［１３．８±３．１ｖｓ４．２±０．９ｍｌ／（ｇ·ｍｉｎ），Ｐ〈０．０１］和脑［２．９±０．４ｖｓ０．８６±０．４ｍｌ／（ｇ·ｍｉｎ），Ｐ〈０．０１］组织的血流量，肝及肾脏次之，对骨骼肌血流无显影响。在本实验所用剂量下，ＨＭＺ对脑血管     

下丘脑胰岛素及其受体在高血压大鼠的变化及与血压的关系

目的 探讨下丘脑胰岛素及其受体在高血压大鼠的变化及与血压的关系.方法 比较自发性高血压大鼠(spontaneous hypertensive rats,SHR)与正常血压Wistar大鼠对照下丘脑的胰岛素含量、胰岛素受体最大结合容量(maximum binding capacity,Bmax)和平衡解离常数(equilibrium dissociation constant,KD),观察下丘脑前区微量注射胰岛素对平均动脉血压(mean arterial pressure,MAP)的影响.结果 下丘脑胰岛素含量SHR高于Wistar大鼠,而血浆胰岛素与Wistar大鼠无明显变化.SHR下丘脑胰岛素受体Bmax显著低于Wistar大鼠,KD值无显著变化.SHR下丘脑前区微量注入0.2 pmol胰岛素,在注射1 h后MAP显著下降,Wistar大鼠组MAP无变化.结论 下丘脑胰岛素在高血压发生发展过程可能起到保护作用,抑制血压的过度升高.     

川芎嗪对新生大鼠离体胰岛分泌胰岛素的影响

目的观察川芎嗪对新生大鼠离体胰岛胰岛素分泌的影响并探讨其作用途径.方法利用放射免疫技术,分别测定不同浓度川芎嗪处理组,川芎嗪处理不同时间组及不同浓度维拉帕米与川芎嗪共同处理组培养的大鼠离体胰岛的基础胰岛素分泌量和高糖刺激的胰岛素分泌量.结果①川芎嗪1.0 mmol/L、2.0 mmol/L、4.0mmol/L作用于胰岛24 h,其基础胰岛素分泌量明显高于对照组(P＜0.05),作用呈剂量依赖性,而高糖刺激的胰岛素分泌量无明显改变(P＞0.05);②川芎嗪1.0 mmoL/L分别作用于胰岛12 h、24 h、36 h后,基础胰岛素分泌量高于对照组(P＜0.05),呈一定的时间依赖性;③维拉帕米25μg/L、50μg/L、100 μg/L与2.0 mmol/L川芎嗪联合作用后基础胰岛素分泌量低于对照组(P＜0.05),且呈剂量依赖性.结论川芎嗪能促进离体培养大鼠胰岛基础胰岛素分泌,其作用可能与激活钙通道有关.     

静脉压增高对大鼠脑血流的影响

目的:研究静脉压增高对脑血流的影响.方法:选择Wistar雄性大鼠20只,行右颈总动脉和右颈外静脉端端吻合.利用激光多普勒扫描技术测定吻合前、后脑局部脑血流(rCBF)和局部脑血流量(rCBV)的变化,并在吻合2wk时结扎动静脉吻合部位,同时测量吻合部位结扎前后rCBF和rCBV.结果:与吻合前比较,左侧大脑半球吻合rCBF,rCBV无显著变化,右侧大脑半球吻合后rCBF,rCBV分别由41.9±10.5和1245.1±710.2增高至43.4±10.3和1561.5±850.1(P＜0.05),但2wk后rCBF降至34.5±8.3(P＜0.05),rCBV增高至1737.9±1041.8(P＜0.05).与吻合部结扎前比较,吻合部结扎后rCBF即刻增高至38.9±6.2(P＜0.05),rCBV即刻降低至1000.7±689.5(P＜0.05).结论:一侧颈总动脉与颈外静脉吻合模型对研究静脉压增高状态下脑缺血具有实用价值,结扎动静脉短路造成静脉压增高可以明显改善局部脑血流.