诱导大鼠肥胖过程中体内激素及ob基因表达水平的变化

目的　研究高能饲料诱导大鼠肥胖的动态过程中,肥胖基因（ｏｂ） ｍ Ｒ Ｎ Ａ 的变化规律和体内一些激素的相互关系。方法　采用 Ｒ Ｎ Ａ 斑点杂交技术检测了大鼠脂肪组织中ｏｂ ｍ Ｒ Ｎ Ａ 水平,放射免疫分析测定大鼠血清中胰岛素及生长激素水平。结果　随大鼠体重（ Ｂ Ｗ） 增加,ｏｂ ｍ Ｒ Ｎ Ａ 水平、胰岛素水平增加,而生长激素水平随大鼠体重增加而下降。结论　ｏｂ ｍ Ｒ Ｎ Ａ 表达水平升高可能是肥胖发生的结果,不是原因;ｏｂ ｍ Ｒ Ｎ Ａ,胰岛素,生长激素三者之间变化规律一致说明,三者之间存在相互作用,或受共同代谢信号调节。     

二甲双胍改善高脂喂养大鼠肝脏脂肪变性和 促进Ｍｆｎ２ｍＲＮＡ 表达的实验研究

摘要：目的　研究二甲双胍对高脂喂养Ｗｉｓｔａｒ大鼠肝脏脂肪变性、胰岛素敏感性和线粒体功能的影响。方
法　２４只雄性Ｗｉｓｔａｒ大鼠分为对照组（ＮＣ）、高脂组（ＨＦ） 和二甲双胍组（ＭＦ），每组８ 只，喂养８ 周
后，以高胰岛素 正常葡萄糖钳夹测定大鼠胰岛素敏感性，取空腹血清测定大鼠天冬氨酸转氨酶（ＡＳＴ）、
丙氨酸氨基转移酶（ＡＬＴ）、甘油三酯（ＴＧ）、空腹血糖（ＦＢＳ），空腹胰岛素（ＦＩＮＳ） 的水平；将大鼠肝
脏组织进行ＨＥ 染色，观察肝脏组织学变化；取肝脏组织，测定肝糖原含量；提取、分离肝细胞线粒体超
氧化物歧化酶，测定线粒体超氧化物歧化酶活性，以及提取肝组织总ＲＮＡ，应用ＲＴ ＰＣＲ 测定肝脏组织
Ｍｆｎ２ｍＲＮＡ 的表达。结果　与ＮＣ 组大鼠比较，ＨＦ 组大鼠肝脏指数、ＴＧ、ＦＢＳ、ＡＬＴ、ＡＳＴ、ＩＮＳ明显
升高，ＭＦ组大鼠上述各指标差异无统计学意义（犘＞０．０５），ＨＦ 组大鼠ＧＩＲ、ＳＯＤ 活性及肝脏组织
Ｍｆｎ２ｍＲＮＡ 表达显著降低（犘＜０．０５）。与ＮＣ 组和ＨＦ 组大鼠分别比较，ＭＦ 组大鼠ＧＩＲ （８．４０±０．５０，
７．２９±０．４０狏狊１２．９２±８．３３）、肝糖原含量（１．７３ ±０．０１，１．８２ ± ０．３１狏狊１２．９２ ± ８．３３）、ＳＯＤ 活性
（１３．７１±２．６７，９．０８±３．１２狏狊１６．７２±４．８０）显著增加（犘＜０．０５）。ＮＣ 和ＨＦ两组间，肝糖原含量差异无
统计学意义（犘＞０．０５）。肝组织ＨＥ 染色，结果显示，ＨＦ 组大鼠肝细胞体积增大，胞质中有脂滴空泡；
ＭＦ组大鼠肝细胞显微结构无显著变化。结论　二甲双胍可以改善高脂诱导的肝脏脂肪变性、增加胰岛素
敏感性，这一作用可能是通过促进肝细胞线粒体融合基因２ （Ｍｆｎ２）表达、改善线粒体功能实现的。
关键词：二甲双胍；肝脏脂肪变性；胰岛素敏感性；线粒体融合素基因２
中图分类号：Ｒ５８７．１　　文献标识码：Ａ　　文章编号：１００９ ６６３９ （２０１６）０９ ０６８１ ０５     

禁食对大鼠肝脏胰岛素样生长因子—I及其结合蛋白—1 mRNA？…

目的 探讨营养状态调节机体生长发育的分子生物学机制。方法 利用Ｎｏｒｔｈｅｒｎ印迹技术,分析禁食对雄性Ｗｉｓｔａｒ大鼠肝胰岛素样生长因子－Ｉ（ＩＧＦ－Ｉ）和胰岛素样生攻因子结合蛋白（ＩＧＦＢＰ－１）基因表达的影响。结果 禁食４８小时后大鼠体重下降１１．８％,血糖下降５０．８％,禁食４８小时后,肝ＩＧＦ－ＩｍＲＮＡ含量下降３２．７％,与此相反,禁食后肝ＩＧＦＢＰ－１ｍＲＮＡ含量逐渐上升,禁食２４小时     

氟化钠致大鼠肾脏脂质过氧化损伤及亚硒酸钠的保护作用

目的研究氟化钠（ＮａＦ）对大鼠肾脏脂质过氧化作用的影响及亚硒酸钠（Ｎａ２ＳｅＯ３）对氟肾脏毒性的保护作用。方法大鼠经饮水加入ＮａＦ（１５ｍｍｏｌ／Ｌ）或／和Ｎａ２ＳｅＯ３（１５μｍｏｌ／Ｌ）染毒１２０天,观察氟在机体的蓄积、排泄,尿酶活性及肾脏脂质过氧化水平的变化。结果氟染毒后,大鼠血氟水平、尿氟水平、骨氟含量,尿谷氨酰转肽酶（γＧＴ）、Ｎ乙酰βＤ氨基葡萄糖苷酶（ＮＡＧ）、琥珀酸脱氢酶（ＳＤＨ）活性及肾脏活性氧自由基（ＯＦＲＳ）相对浓度、脂质过氧化降解产物丙二醛（ＭＤＡ）含量均显著升高,谷胱甘肽过氧化物酶（ＧＳＨＰｘ）活性及ＧＳＨ含量显著下降。同时补加亚硒酸钠,可促进尿氟排泄,降低血氟水平及骨氟含量,降低尿酶γＧＴ、ＮＡＧ、ＳＤＨ活性和肾脏ＯＦＲＳ、ＭＤＡ含量,同时提高肾脏ＧＳＨＰｘ活性,但对ＧＳＨ含量影响不显著。结论氟化钠引起肾脏损伤与其诱导脂质过氧化作用增强有关,亚硒酸钠对氟化钠致肾脏毒性具有拮抗作用。     

IGF-1与矽肺纤维化的关系

目的了解胰岛素样生长因子１（ＩＧＦ１）与矽肺纤维化的关系。方法用免疫组化（ＳＡＢＣ法）技术对大白兔染石英尘后９０天、１８０天兔肺组织ＩＧＦ１表达及矽结节数目进行研究。结果染尘后９０天、１８０天兔肺组织ＩＧＦ１阳性表达率分别为７０％和１００％（Ｐ＜００１）,染尘后９０天、１８０天兔肺组织矽结节平均数分别为１９８±２０和３０３±１１（Ｐ＜０００５）,肺组织ＩＧＦ１阳性表达强度与肺纤维化程度存在明显相关（ｒ＝０６８５７）。结论ＩＧＦ１可能在矽肺纤维化形成过程中发挥重要作用。     

血清胰岛素样生长因子与胎鼠生长发育的关系

目的 探讨血清胰岛素样生长因子（ＩＧＦｓ）与胎儿出生体重、身长、胎盘重量和血糖浓度的关系。方法 ２１只孕鼠分为宫内生长迟缓组（ＩＵＧＲ）和对照组。检测２组胎鼠血清ＩＧＦ－Ｉ、ＩＧＦ－ＩＩ水平，血糖浓度及胎鼠出生体重、身长、并进行比较和相关分析。结果 ＩＵＧＲ胎鼠的血清ＩＧＦ－Ｉ、ＩＧＦ－Ⅱ、血糖浓度、胎盘重量及出生体重、身长均较对照组明显降低（Ｐ〈０．０１）；ＩＧＦ－Ｉ、ＩＧＦ－Ⅱ水平与出生体重、     

正常血压糖耐量低减患者尿白蛋白排出率相关因素分析

对２１７例正常血压糖耐量低减（ＩＧＴ）患者及１６０例下沉人尿白蛋白排出率９ＵＡＥＲ）进行了测定,且应用多元逐步回归分析法对下沉血压ＩＧＴ患者ＵＡＥＲ可能的危险因素进行了探讨。结果显示ＩＧＴ患者ＵＡＥＲ明显高于正常对照组,且ＩＧＴ２的收缩压（ＳＢＰ）、舒张压（ＤＢＰ）、体质指数（ＢＭＩ）、腰臀比值（ＷＨＲ）及血清服糖后２ｈ胰岛素均明显高于对照组,而胰岛素敏感指数（ＩＳＩ）明显低于正常对照组。多元逐步     

IFN-γ、Epo与类风湿性关节炎贫血相关性研究

为探讨类风湿性关节炎（ＲＡ）伴慢性疾病性贫血（ＡＣＤ）血清中ＩＦＮ－γ和Ｅｐｏ变化,及其发病中作用的可能机制。采用ＥＬＩＳＡ法检测ＲＡ患者血清中ＩＦＮ－γ及ＲＡ伴ＡＣＤ患者的Ｅｐｏ变化。并以人肝癌细胞株ＨｅｐＧ２为模型,观察ＩＦＮ－γ对钴盐（ＣｏＣＬ２）诱导的Ｅｐｏ产生的影响。与正常对照组比较,ＲＡ及伴ＡＣＤ者血清中ＩＦＮ－γ显著增高,与血红蛋白浓度呈负相关。ＲＡ伴ＡＣＤ者的Ｅｐｏ水平高于正常对照     

小儿单纯性肥胖症胰腺内分泌功能研究

目的:探讨单纯性肥胖(SO)患儿胰腺内分泌功能。方法:采用放射免疫分析法测定SO患儿空腹和摄入液体实验餐60 min时外周血胰岛素、胰高血糖素和生长抑素(SS)水平。结果:与对照组比较,SO患儿空腹时血中胰岛素、胰高血糖素明显升高(P<0.01),而SS水平无明显差异(P>0.05),其餐后血中胰岛素、胰高血糖素也明显升高(P<0.01),而SS水平则明显降低(P<0.01);空腹与餐后比较,SO患儿餐后血中胰岛素水平明显升高(P<0.01),胰高血糖素及SS水平无明显变化(P>0.05),对照组则血中胰岛素和SS水平升高(P<0.01),胰高血糖素水平无明显变化(P>0.05)。结论:SO患儿存在明显的胰腺内分泌功能紊乱,应引起高度重视。     

原发性高血压伴肥胖病人胰岛素水平观察

目的：探讨原发性高血压伴肥胖病人胰岛素水平变化的临床意义。方法：３５例原发性高血压伴肥胖病人（Ａ组）、２６例单纯性肥胖病人（Ｂ组）、２８名正常人（Ｃ组），以ＯＧＴＴ、ＩＮ－ＳＴ观察糖负荷前后血糖和胰岛素水平变化，并计算胰岛素敏感指数（ＩＳＩ），胰岛素曲线下面积（Ａ）。结果：⑴三组均呈正常糖耐量曲线，其峰值分别为Ａ组＞Ｂ组＞Ｃ组；Ａ组中检出ＩＧＴ９例（２５７％）；⑵Ａ、Ｂ组ＩＮＳ明显高于ＦＩＮＳ（ｘ±２ｓ）值，且各时点值显著增高，ＩＳＩ明显下降，Ａ值明显增高（Ｐ＜００５，０００１）。Ａ、Ｂ两组间于２ｈ、３ｈ点亦有显著性差异。结论：原发性高血压伴肥胖症病人存在着明显高胰岛素血症和胰岛素抵抗，易诱发ＩＧＴ和ＤＭ，故联合检测ＯＧＴＴ、ＩＮ－ＳＴ对临床干预治疗十分重要。     

Investigation of possible involvement of several genes related to development of hepatocarcinogenesis in rats

A comparative study on the possible involvement of several genes in the susceptibility of chemical carcinogenesis was carried out using carcinogen-resistant DRH rat and -sensitive Donryu and F344 rats. Previously, we observed that the induction of glutathione S-transferase placental form (GST-P) in the liver of Donryu rats by 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) was significantly greater than that of DRH rats. In the present study, we tentatively determined base sequences of the enhancer region including GPE-I and GPE-II (GST-P enhancers I and II) of GST-P genes of DRH, Donryu and F344 rats, but we did not observe any nucleotide polymorphism around these regions. Furthermore, the mRNA levels of silencer binding protein (NFA-1) for the GST-P promoter of rat liver were also similar in the DRH and Donryu rats. Since clonal expansion of putative preneoplastic GST-P-positive foci in the DRH rat liver was significantly suppressed during 3'-Me-DAB administration, we examined whether two opposite growth controlling factors, TGF-alpha and TGF-beta, may participate in such suppression of growth. It was supposed that mannose 6-phosphate/insulin-like growth factor 2 receptor (M6P/IGF2R), at least in part, activates TGF-beta preproprotein. However, we observed that the levels of M6P/IGF2R mRNA in the livers of DRH were not higher than those of Donryu rats after being fed 3'-Me-DAB for 8 weeks. Another important factor in the carcinogenesis is insulin-like growth factor II itself. Although liver tumors induced by 3'-Me-DAB in F344 had high levels of IGF-II mRNA, little IGF-II gene expression existed in normal adult livers of Donryu, F344 and DRH rats. High levels of IGF-II mRNA were detected similarly in the livers of neonates from all these three strains of rats. Finally, we detected a significant increase of AFP (alpha-fetoprotein) mRNA in the livers of Donryu rats around 6 to 8 weeks from the start of 3'-Me-DAB feeding, which is in parallel with detrimental effects of this carcinogen on these rats. A reduced induction of AFP mRNA was observed in DRH rats under the same conditions. Further study will be needed to explain the lower tumor susceptibility in the DRH rat.     

IGF-1增加脓毒症大鼠骨骼肌葡萄糖载体及其表达

目的:探讨胰岛素样生长因子-1(IGF-1)对脓毒症大鼠血浆应激激素及骨骼肌葡萄糖载体-4(GLUT-4)和mRNA表达的影响.方法:将SD大鼠采用盲肠结扎穿孔法(CLP)建立腹腔感染及颈静脉置管肠外营养(PN)模型后,随机分为脓毒症组(n=10)、PN组(n=10)和IGF-1组(n=10),另设正常组(n=10)仅行颈静脉置管输液.正常组和脓毒症组给予等渗盐水,自由进食和饮水,PN组给予营养支持,IGF-1组为PN IGF-1静脉注射,连续5d.第6 d测定血糖、胰岛素、高血糖素和IGF-1水平;免疫组化法测定骨骼肌GLUT-4及Real-Time PCR法测定GLUT-4 mRNA表达.结果:脓毒症大鼠血浆葡萄糖、胰岛素、高血糖素明显升高,IGF-1明显下降(P＜0.01).IGF-1组前三者较脓毒症组和PN组明显降低,IGF-1则明显升高(P＜0.05).脓毒症组骨骼肌GLUT-4及mRNA表达明显降低(P＜0.01);IGF-1组GLUT-4及mRNA表达较脓毒症组和PN组明显增加(P＜0.01).结论:IGF-1可改善应激激素之间的平衡,明显增加脓毒血症大鼠骨骼肌GLUT-4蛋白和mRNA的表达.     

Progressive adaptation of the endocrine pancreas during long-term protein deficiency in rats: effects on blood glucose homeostasis and on pancreatic insulin, glucagon and somatostatin concentrations

Blood glucose, plasma insulin and glucagon, as well as pancreatic insulin, glucagon and somatostatin contents, were measured in control (C group, 18% casein), deprived (D group, 5% casein) and pair-fed (PF) rats at seven intervals during 23 wk after weaning (wk 0). In C rats, plasma and pancreatic insulin showed parallel variations, in D rats, plasma insulin increased normally until wk 3 after weaning, dropped from wk 3 to 8 and was higher in wk 16 and 23 than in wk 8, while pancreatic insulin increased linearly after a significant drop between wk 0 and 1. Insulin variations in D rats were related to protein deficiency until wk 5, but only to energy deficiency thereafter. Circulating and pancreatic glucagon dropped identically for the three groups until wk 5: its role in adaptation to malnutrition is quite irrelevant, although a dysregulation of its secretion was noted. Protein-energy malnutrition induced an increase of pancreatic somatostatin content that was due to the energy deficiency. On the basis of the insulin-to-glucagon ratio, three phases of adaptation to protein-energy malnutrition appeared. From wk 0 to 3, the metabolic priority was growth, whereas glucose homeostasis was secondary, accounting for the early hypoglycemia. From wk 3 to 8 survival was the main priority. After wk 8, the various biochemical parameters stabilized, and growth was parallel to that of normal animals. Protein-energy malnutrition was responsible for a dissociated adaptation of pancreatic hormones.     

Developmental increases in rat hepatic microsomal UDP-glucuronosyltransferase activities toward xenoestrogens and decreases during pregnancy

Xenoestrogens, such as bisphenol A and diethylstilbestrol, are glucuronidated by an isoform of UDP-glucuronosyltransferase named UGT2B1 in the livers of adult male rats. In this study, we found that nonylphenol and octylphenol are also conjugated with glucuronic acid by adult rat liver microsomes. Although UDP-glucuronosyltransferase activities toward these xenoestrogens were not detected in the fetal rat liver, a linear increase in enzymatic activities during neonatal development was observed. At 3 weeks after birth, the activities had reached the same level as that of adult rats. The protein and mRNA contents of UGT2B1 also were not detected in the fetal rat liver, but a developmental increase in newborn rat liver was detected by Western and Northern blotting analysis. Additionally, rat hepatic microsomal UDP-glucuronosyltransferase activities toward these xenoestrogens were reduced by about half during pregnancy of mother rats. The results suggest that the reproductive organs of fetal and early-stage neonatal rats, which are sensitive to sex hormones, face a high risk of exposure to free active xenoestrogens.     

Loss of the pregnancy-induced rise in cortisol concentrations in the ewe impairs the fetal insulin-like growth factor axis

Maternal cortisol levels increase during pregnancy. Although this change is important for optimal fetal growth, the mechanisms of the changes in growth remain unclear. The hypothesis examined was that alterations in maternal plasma cortisol concentrations are associated with changes in the fetal insulin-like growth factor (IGF) axis. Pregnant ewes in late gestation (115 ± 0.4 days) were studied: six control animals, five ewes given 1 mg kg(-1) day(-1) cortisol (high cortisol) and five adrenalectomised ewes given 0.5-0.6 mg kg(-1) day(-1) cortisol (low cortisol). Blood samples were taken throughout the experiment and at necropsy (130 ± 0.2 days) and fetal liver was frozen for mRNA analysis. Fetal IGF-I and insulin plasma concentrations were lower and insulin-like growth factor-binding protein-1 (IGFBP-1) concentrations were higher in the low cortisol group compared with those in the control group (P < 0.05). Fetal liver IGF-II and IGFBP-3 mRNA were decreased in low cortisol animals compared with controls (P < 0.05). There were no significant changes in these parameters in the high cortisol group, and there were no changes in fetal liver IGF-I, growth hormone receptor, IGF-I receptor, IGF-II receptor, IGFBP-1 or IGFBP-2 mRNA levels between the groups. These data suggest that reduced fetal IGF availability contributes to reduced fetal growth when maternal cortisol secretion is impaired, but not during exposure to moderate increases in cortisol.     

新发现的SOCS蛋白家族:揭示了创伤和营养不良时代谢异常的机理

细胞因子信号传递抑制体(SOCS)是一组新近才被认识的蛋白，它们经细胞因子诱导而释放，再反馈抑制细胞因子在细胞内的信号传递。以往的工作显示：内毒素能显提高SOCS在大鼠肝脏中的表达，这又同内毒素引起的生长激素的拮抗密切相关。     

Chronic prenatal ethanol exposure alters expression of central and peripheral insulin signaling molecules in adult guinea pig offspring

Maternal ethanol consumption during pregnancy can produce a range of teratogenic outcomes in offspring. The mechanism of ethanol teratogenicity is multi-faceted, but may involve alterations in insulin and insulin-like growth factor (IGF) signaling pathways. These pathways are not only important for metabolism, but are also critically involved in neuronal survival and plasticity, and they can be altered by chronic prenatal ethanol exposure (CPEE). The objective of this study was to test the hypothesis that CPEE alters expression of insulin and IGF signaling molecules in the prefrontal cortex and liver of adult guinea pig offspring. Pregnant Dunkin-Hartley-strain guinea pigs received ethanol (4 g/kg maternal body weight/day) or isocaloric-sucrose/pair-feeding (nutritional control) throughout gestation. Fasting blood glucose concentration was measured in male and female offspring at postnatal day 150–200, followed by euthanasia, collection of prefrontal cortex and liver, and RNA extraction. IGF-1, IGF-1 receptor (IGF-1R), IGF-2, IGF-2 receptor (IGF-2R), insulin receptor substrate (IRS)-1, IRS-2, and insulin receptor (INSR) mRNA expression levels were measured in tissues using quantitative real-time PCR. The mean maternal blood ethanol concentration was 281 ± 15 mg/dL at 1 h after the second divided dose of ethanol on GD 57. CPEE resulted in increased liver weight in adult offspring, but produced no difference in fasting blood glucose concentration compared with nutritional control. In the liver, CPEE decreased mRNA expression of IGF-1, IGF-1R, and IGF-2, and increased IRS-2 mRNA expression in male offspring only compared with nutritional control. Female CPEE offspring had decreased INSR hepatic mRNA expression compared with male CPEE offspring. In the prefrontal cortex, IRS-2 mRNA expression was increased in CPEE offspring compared with nutritional control. The data demonstrate that CPEE alters both central and peripheral expression of insulin and IGF signaling molecules at the mRNA level, which may be related to metabolic dysregulation in adult offspring. Furthermore, altered insulin and IGF signaling may be a mechanism of ethanol neurobehavioral teratogenicity.