肝复康对大鼠肝组织血小板衍生生长因子表达及对胶原合成的影响

目的探讨中药肝复康对大鼠肝组织血小板衍生生长因子(PDGF)表达的影响及其对胶原合成的调节作用。方法制备四氯化碳诱导的肝纤维化大鼠模型,应用肝复康干预;测定各组大鼠血清白蛋白、球蛋白、谷丙转氨酶和谷草转氨酶的含量;采用免疫组织化学法检测肝组织PDGF表达;采用RT-PCR法测定肝组织及HSC-T6细胞Ⅰ型胶原mRNA水平的变化。结果治疗组与模型组相比,血清谷丙转氨酶、谷草转氨酶和球蛋白水平均降低,白蛋白及白/球比例则升高(P<0.01);模型组肝组织PDGF的表达上调,而肝复康治疗组表达则下调(P<0.01);模型组肝组织及HSC-T6细胞Ⅰ型胶原mRNA水平较正常对照组明显上调(P<0.01),而肝复康治疗组则明显下调(P<0.01)。结论肝复康通过降低PDGF的表达,抑制Ⅰ型胶原的合成,对肝纤维化具有一定的防治作用。     

北五味子多糖对高脂血症大鼠肝损伤的影响

目的探讨北五味子多糖(SCP)对高脂饮食诱导肝损伤大鼠肝功能的保护作用。方法采用高脂饲料喂养16 w诱发高脂血症大鼠模型,随机分为模型组及SCP治疗组,另设正常对照组以及正常+SCP组。SCP(50 mg/kg)灌胃给药12 w,检测各组动物血清中总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、谷丙转氨酶(ALT)、谷草转氨酶(AST)水平,肝组织中TG和TC水平;苏木素-伊红(HE)染色观察药物对肝组织病理学改变的影响。结果与正常对照组比较,模型组大鼠血清中TC、TG、LDL-C、ALT及AST水平显著增高(P<0.01),肝组织中TG和TC水平显著增高(P<0.01)。与模型组比较,SCP显著降低了大鼠血清TC、TG、LDL-C水平(P<0.05或P<0.01)、ALT、AST水平(P<0.01),降低肝组织中TG和TC水平(P<0.01),而对正常大鼠血脂、肝脂质和肝功能没有明显影响。HE染色显示模型组大鼠肝小叶结构紊乱,出现明显的肝细胞脂肪变性;SCP组肝小叶结构基本正常,肝脏脂肪变性明显减轻。结论 SCP可改善高脂血症大鼠脂质代谢紊乱,改善肝功能,减轻肝损伤。     

动态观察非酒精性脂肪肝大鼠肝脏抵抗素的表达

目的观察非酒精性脂肪性肝病(NAFLD)模型大鼠肝脏抵抗素mRNA的动态表达,探讨抵抗素在大鼠NAFLD发病中的作用。方法雄性Wistar大鼠48只随机分为正常对照组(C组)和模型组(M组),C组给予普通饲料,M组给予高脂饮食喂养,分别于9,13,17周末处死各组大鼠。测定大鼠血清肿瘤坏死因子α(TNF-α)、游离脂肪酸(FFA)、甘油三酯(TG)、总胆固醇(TC),以及肝组织TG,测定空腹血糖(FBS)、空腹胰岛素(FINS),并计算胰岛素敏感指数(ISI)。应用半定量RT-PCR检测各组大鼠肝脏组织抵抗素mRNA的表达;HE染色观察肝脏组织病理变化并计算炎症活动度计分。结果第9,13,17周末M组大鼠抵抗素mRNA相对表达量显著高于C组(P<0.01),且随造模时间延长表达量显著增加(P<0.01)。M组大鼠血清FFA、TG、TC、TNF-α及肝组织TG较同期C组均显著升高(P<0.01),ISI显著降低(P<0.01)。相关分析显示,M组大鼠各时点肝脏抵抗素mRNA相对表达量与血清TNF-α水平均呈正相关(r=0.787,0.888,0.873,P<0.05,P<0.01,P<0.01);在第9,13周末与肝脏炎症活动度计分呈正相关(r=0.861,0.892,P<0.01);而与ISI在第9周末呈负相关(r=-0.843,P<0.01)。结论高脂饮食NAFLD模型大鼠肝脏抵抗素基因表达随造模时间的延长而增加,抵抗素可以通过胰岛素抵抗及对炎症因子的调控参与NAFLD的发生发展。     

叶酸对2型糖尿病大鼠胸主动脉内皮功能的影响

目的探讨长期补充叶酸对2型糖尿病大鼠胸主动脉内皮功能的影响及其作用机制。方法将2型糖尿病大鼠37只分为模型组(12只)、小剂量叶酸组(12只)和大剂量叶酸组(13只),另11只正常大鼠为正常对照组,叶酸干预11周后,剪尾采血分别检测血清一氧化氮、超氧化物歧化酶及丙二醛水平,并取胸主动脉制备主动脉环进行离体血管环反应性测定。结果模型组大鼠血清一氧化氮和超氧化物歧化酶水平明显低于正常对照组(P<0.01),而血清丙二醛水平明显高于正常对照组(P<0.01);补充叶酸11周后,小剂量叶酸组及大剂量叶酸组血清一氧化氮及超氧化物歧化酶水平均较模型组有明显增高(P<0.05或P<0.01),而血清丙二醛水平较模型组明显降低(P<0.01)。在每一个乙酰胆碱累积浓度下,模型组大鼠胸主动脉环的舒张度均较正常对照组明显减低(P<0.05或P<0.01),而小剂量叶酸组和大剂量叶酸组大鼠胸主动脉环的舒张度则均较模型组明显增高(P<0.05或P<0.01),小剂量叶酸组大鼠胸主动脉环的舒张度与大剂量叶酸组相比差异无显著性。结论长期补充叶酸对2型糖尿病大鼠血管内皮功能损伤具有明显预防作用,叶酸可能通过增加机体一氧化氮合成从而提高血清一氧化氮活性和提高机体抗氧化能力来预防2型糖尿病大鼠血管内皮功能损伤的发生。     

细胞色素P450 2E1在脂肪性肝炎大鼠肝组织的表达及作用

目的探讨细胞色素P4502E1(CYP2E1)在脂肪性肝炎大鼠肝组织内的表达和作用。方法通过高脂饮食和逐渐增加酒精灌胃量持续16周建立Wister大鼠脂肪性肝炎动物模型,造模结束时检测模型组和正常组动物血脂、游离脂肪酸(FFA)和肝组织丙二醛(MDA)、超氧化物歧化酶(SOD)、还原性谷胱甘肽(GSH)含量;免疫组化标记检测肝组织CYP2E1表达;RT-PCR法检测CYP2E1 mRNA的水平。结果实验结束时,模型组大鼠血脂和血清FFA较正常组显著增高(P<0.01);肝组织MDA较正常组显著增高(P<0.01),而SOD和GSH较正常组明显减低(P<0.01);肝组织内CYP2E1及其基因表达较正常组显著升高(P<0.01),并与肝组织内MDA、脂肪变程度、炎症计分呈明显正相关(r值分别为0.652,0.913和0.943,P值均<0.05),与SOD、GSH呈显著负相关(r值分别为-0.916,-0.766,P<0.01)。结论脂肪性肝炎大鼠肝脏内CYP2E1呈诱导表达状态,后者可能通过增强氧应激,降低抗氧化能力,加重脂质过氧化等过程参与了脂肪性肝炎的形成。     

干扰素-γ对大鼠肝组织中的MMP-13与TIMP-1表达的干预作用

目的 探讨干扰素-γ对实验性大鼠肝组织中的基质金属蛋白酶-13(MMP-13)与金属蛋白酶组织抑制因子-1(TIMP-1)表达的影响.方法 SD大鼠22只,随机分为3组:正常组(7只)、模型组(6只)和干扰素-γ组(9只);用四氯化碳制备大鼠肝纤维化模型,在10周末处死各组大鼠,取肝脏进行HE染色,并运用半定量逆转录聚合酶链反应(RT-PCR)检测肝组织中MMP-13 mRNA与TIMP-1 mRNA的表达量.结果 MMP-13 mRNA的表达,与正常组对比,模型组和干扰素-γ组的MMP-13 mRNA的表达量增高(P<0.01),但模型组和干扰素-γ组之间还不能认为有统计学差别(P>0.01);而TIMP-1 mRNA表达与正常组相比,模型组和干扰素-γ组中的TIMP-1 mRNA的表达都升高(P<0.01),而且模型组中的TIMP-1 mRNA表达量比干扰素-γ组高(P<0.01).在肝纤维化病理学观察的量化秩和分析中,各组之间的差别明显(P<0.005).结论 干扰素-γ逆转肝纤维化的机制可能是减少肝纤维化大鼠肝脏中的TIMP-1 mR-NA的表达,从而逆转肝纤维化.     

解聚复肾宁对糖尿病大鼠肾组织基质金属蛋白酶-9、金属蛋白酶组织抑制剂-1表达的影响

目的观察解聚复肾宁(JJFSN)对糖尿病(DM)大鼠肾组织基质金属蛋白酶-9(MMP-9)、金属蛋白酶组织抑制剂-1(TIMP-1)表达及肾脏保护作用机制。方法建立STZ诱导的DM SD大鼠模型,将成模DM大鼠随机分成4组:模型组、JJFSN组、厄贝沙坦组、JJFSN+厄贝沙坦组,同时设正常对照组。各组大鼠采用相应的干预措施处理12 w。检测各组大鼠第12周时肾重/体重、血糖、尿素氮、血肌酐、尿白蛋白排泄率(UAER),免疫组化法检测肾组织MMP-9、TIMP-1表达,透射电镜观察肾脏超微结构。结果模型组肾脏超微结构改变明显,血糖、UAER、尿素氮、血肌酐、肾重/体重显著增高。模型组大鼠肾组织TIMP-1的表达较正常对照组明显上调(P<0.01),JJFSN组、厄贝沙坦组、JJFSN+厄贝沙坦组肾组织TIMP-1表达明显下调(P<0.01),但仍高于正常对照组(P<0.01),JJFSN+厄贝沙坦组下调最明显(P<0.01)。DM模型组大鼠肾组织MMP-9的表达较正常对照组明显下调(P<0.01),解聚复肾宁组、厄贝沙坦组、解聚复肾宁+厄贝沙坦组肾组织MMP-9表达明显上调(P<0.01),但仍低于正常对照组(P<0.01),解聚复肾宁+厄贝沙坦组上调最明显(P<0.01)。结论 MMP-9、TIMP-l的表达变化与肾小球细胞外基质(ECM)降解减少相关,可能促进了糖尿病肾病(DN)的发生,JJFSN可能通过干预这种表达变化,减缓DN的发生和发展。     

血必净对内毒素血症大鼠炎症反应的保护作用及心肌AngⅡ和Toll受体-4表达的影响

目的探讨血必净(XBJ)对内毒素血症(ETM)大鼠炎症反应的保护作用及心肌Toll受体-4(TLR-4)表达的影响。方法选取8周龄的雄性SD大鼠30只并采用阴茎背静脉注射脂多糖(LPS)诱导ETM大鼠模型。将ETM大鼠随机分为LPS组:LPS+XBJ组和LPS+地塞米松(DEX)组(n=10),LPS+XBJ组和LPS+DEX组在注射LPS的同时分别给予XBJ 5 ml/kg和DEX 5 mg/kg。选取同期的10只正常大鼠作对照,仅给予等体积的生理盐水。3 h后断头取血并取心肌于液氮保存,采用酶联免疫吸附法检测各组血浆炎症因子(TNF-α、CRP和IL-6)水平,放射免疫法检测心肌组织AngⅡ水平;采用RT-PCR法和免疫印迹法检测心肌组织中TLR-4 mRNA和蛋白水平。结果与对照组相比,LPS组的血浆炎症因子及心肌组织AngⅡ、TLR-4 mRNA和蛋白水平均升高(P<0.05);除血浆CRP外,XBJ处理可降低LPS诱导的其余指标升高(P<0.05),但与对照组的差异仍有统计学意义(P<0.05);除血浆TNF-α和IL-6外,LPS+XBJ组的其余指标均高于LPS+DEX组。结论血必净可抑制ETM大鼠的炎症反应及AngⅡ,同时可降低TLR-4表达,对ETM有较好的保护作用。     

柴胡皂苷A对抑郁模型大鼠海马神经细胞凋亡的保护作用

目的探讨柴胡皂苷A对抑郁模型大鼠海马神经细胞凋亡的保护作用及机制。方法 60只SD雄性大鼠随机分为正常对照组、模型组、西药组、中药组;采用慢性不可预见性应激刺激结合孤养方式建立抑郁模型;利用敞箱实验与糖水偏爱度检测大鼠行为学改变;采用电镜观察大鼠脑海马区超微结构变化;应用免疫组化与RT-PCR检测大鼠海马区脑源性神经生长因子(BDNF)蛋白及基因的表达水平。结果与正常对照组相比,模型组水平运动得分、垂直运动得分和糖水偏爱度明显降低(P<0.01,P<0.001),与模型组比较,西药组和中药组水平运动得分、垂直运动得分和糖水偏爱度均明显升高(P<0.05,P<0.001);与正常对照组相比,模型组大鼠海马区BDNF mRNA与蛋白表达明显下调(P<0.05),与模型组相比,西药组、中药组海马区BDNF mRNA与蛋白表达明显上调(P<0.05)。结论柴胡皂苷A抗抑郁症的作用机制可能与其促进海马区BDNF蛋白与mRNA的活性和表达,进而减少神经细胞凋亡有关。     

薏苡仁多糖对2型糖尿病大鼠主动脉内皮素1基因表达的影响

目的观察薏苡仁多糖对实验性糖尿病血管并发症大鼠主动脉内皮素1mRNA表达调控的影响。方法采用链脲佐菌素腹腔注射(75mg/kg)和高热量饲料喂养建立2型糖尿病并发动脉粥样硬化大鼠模型,应用RT-PCR半定量分析大鼠主动脉内皮素1mRNA的表达变化。结果模型组大鼠主动脉内皮素1mRNA表达量为0.72±0.10,明显高于正常组的0.39±0.01(P<0.01),经给药处理6个月后,与模型组的表达量比较,各给药组大鼠主动脉内皮素1mRNA有不同程度的下调(P<0.05),其中薏苡仁多糖注射组的表达量0.49±0.12与模型对照组比较有非常显著性差异(P<0.01)。结论糖尿病血管并发症的发生可能与内皮素1mRNA表达上调有关,薏苡仁多糖保护糖尿病血管内皮损伤可能与其下调内皮素1mRNA表达的作用相关。     

一氧化氮吸入对内毒素肺损伤大鼠肺组织糖皮质激素受体的影响

目的:观察一氧化氮吸入(INO)对肺损伤时肺组织内糖皮质激素受体(GR)的影响.方法:将30只大鼠随机分成对照组、内毒素组(LPS)、地塞米松治疗组(DEX)、一氧化氮吸入组(INO)、地塞米松 一氧化氮吸入组(DEX INO),每组6只.通过内毒素静脉注射制备大鼠肺损伤模型,观察不同干预方式对肺组织GR表达的影响.结果:肺损伤后肺组织GR表达下降,予以干预治疗后GR表达增多,其中以INO作用最明显.结论:肺损伤大鼠肺组织内GR降低,与糖皮质激素(GC)亲和力下降,出现激素抵抗现象,影响激素的抗炎效果.一氧化氮吸入(INO)可以增高GR的表达,促进GC-GR复合体的形成,提高GC的抗炎效果.     

Differential regulation of type II corticosteroid receptor messenger ribonucleic acid expression in the rat anterior pituitary and hippocampus

The present study was designed to characterize the regulation of the type II corticosteroid receptor (GR) mRNA in two tissues involved in the control of the hypothalamic-pituitary-adrenal axis. We have used a solution hybridization/S1 nuclease protection assay to quantitate GR mRNA levels in the rat hippocampus and anterior pituitary after CRF, dexamethasone (DEX), or corticosterone (CORT) treatment. In general, hippocampal GR mRNA levels increased after removal of endogenous corticosteroids by surgical adrenalectomy and decreased in response to glucocorticoid treatment. More specifically, in the hippocampus 1) GR mRNA expression was decreased when adrenalectomized (ADX) animals were replaced with a relatively low dose of CORT, but not with a low dose of DEX; 2) acutely, CRF was more effective than DEX in decreasing the levels of GR mRNA in intact animals; however, under the same paradigm in ADX animals, DEX decreased the level of GR mRNA, whereas CRF was ineffective; and 3) in contrast to the decrease in GR mRNA levels observed after acute and low doses of glucocorticoid treatment, chronic treatment with either DEX or CORT did not change the level of hippocampal GR mRNA. These results suggest that in the hippocampus the decrease in GR mRNA expression after CRF treatment is probably via the release of glucocorticoids, and that this tissue is more sensitive to endogenous glucocorticoids than DEX. Anterior pituitary GR mRNA was differentially regulated compared with that in the hippocampus. In marked contrast to Gr mRNA in the hippocampus, ADX did not alter anterior pituitary GR mRNA expression, and glucocorticoid treatment led to an increase in GR mRNA levels. In the anterior pituitary 1) glucocorticoid treatment led to an increase in GR mRNA expression, when replaced with a relatively low dose of DEX, but not when replaced with a low dose of CORT; 2) acutely, neither CRF nor DEX altered levels of GR mRNA in intact animals; however, under the same paradigm DEX increased levels in ADX animals; and 3) chronic DEX or CORT treatment of intact animals elevated levels of anterior pituitary GR mRNA. In summary, these data have demonstrated tissue-specific regulation of GR mRNA in the hippocampus and anterior pituitary, which is dependent on both the dose and length of treatment and, in addition, on the glucocorticoid itself.     

11β-HSD1在糖皮质激素联合高脂喂养大鼠胰岛素抵抗中的作用

目的 通过糖皮质激素联合高脂喂养建立胰岛素抵抗动物模型,探讨11β-羟类固醇脱氢酶1(11β-HSD1)在该模型中的表达和意义.方法 32只雄性Wistar大鼠,按体重随机区组法分为对照组、地塞米松组、高脂饮食组、高脂+地塞米松组(HFD+ DEX组),每组8只.对照组和地塞米松组喂以普通饲料,高脂饮食组和HFD+ DEX组喂以高脂饲料,8周后地塞米松组和HFD+ DEX组辅以地塞米松刺激,12周后进行胰岛素耐量试验,检测血糖、血脂、血胰岛素及皮质酮水平,计算肝指数、内脏肥胖指数及稳态模型评估-胰岛素抵抗(HOMA-IR)指数,检测11β-HSD1基因及蛋白表达情况.结果 与对照组相比,其余3组均出现胰岛素抵抗,表现为:胰岛素耐量试验不敏感(注射胰岛素30 min后对照组、高脂饮食组、地塞米松组和HFD+ DEX组血糖值分别下降了44.15％,28.14％,32.58％,13.53％)、高血糖、高胰岛素血症、血脂紊乱(总胆固醇、甘油三酯及游离脂肪酸升高,高密度脂蛋白-胆固醇降低)、HOMA-IR指数、肝指数及内脏肥胖指数升高,且HFD+ DEX组各项指标变化幅度最大(F=10.89～213.20,P＜0.05或P＜0.01).另外,与对照组相比,其余3组内脏脂肪组织11β-HSD1基因及蛋白表达水平也明显升高,且HFD+ DEX组明显高于高脂饮食组及地塞米松组(F =32.64～116.00,P均＜0.01).结论 地塞米松联合高脂饮食喂养可成功建立大鼠胰岛素抵抗模型,内脏脂肪组织中11β-HSD1基因及蛋白表达升高,可能与胰岛素抵抗的发生密切相关.     

Cytosolic glucocorticoid receptor in the testis of Bufo arenarum: seasonal changes in its binding parameters

Glucocorticoids (GC) are the hormonal mediators of stress. In mammals, high levels of GC have negative effects on reproductive physiology. For instance, GC can inhibit testicular testosterone synthesis by acting via glucocorticoid receptors (GR), the extent of the inhibition being dependent on GC levels. However, the effect of GC on testicular function and even the presence of GR in amphibians are still unclear. The purpose of this work was to characterise testicular cytosolic GR in Bufo arenarum, determining the seasonal changes in its binding parameters as well as the intratesticular localisation. The binding assays were performed in testis cytosol with [3H]dexamethasone (DEX) and [3H]corticosterone (CORT). Binding kinetics of DEX and CORT fitted to a one-site model. Results were expressed as means +/- standard error. Apparent number of binding sites (Bapp) was similar for both steroids (Bapp DEX = 352.53 +/- 72.08 fmol/mg protein; Bapp CORT = 454.24 +/- 134.97 fmol/mg protein) suggesting that both hormones bind to the same site. Competition studies with different steroids showed that the order of displacement of [3H]DEX and [3H]CORT specific binding is: DEX approximately RU486 approximately deoxycorticosterone (DOC) > CORT > aldosterone > RU28362 > progesterone > 11-dehydroCORT. The affinity of GR for DEX (Kd = 11.2 +/- 1.5 nM) remained constant throughout the year while circulating CORT clearly increased during the reproductive season. Therefore, testis sensitivity to GC action would depend mainly on inactivating mechanisms (11beta-hydroxysteroid dehydrogenase type 2) and CORT plasma levels. Since total and free CORT are higher in the reproductive than in the non-reproductive period, the magnitude of GC actions could be higher during the breeding season. The intratesticular localisation of the GR was determined after separation of cells by a Percoll density gradient followed by binding assays in each fraction. DEX binds to two different fractions corresponding to Leydig and Sertoli cells. In conclusion, in the testis of B. arenarum GC could regulate the function of both cellular types particularly during breeding when CORT reaches the highest plasma concentration.     

重症肌无力患者糖皮质激素受体检测的临床价值

目的：探讨糖皮质激素受体（GR）数对预测糖皮质激素（GC）疗效的价值。方法：30例重症肌无力（MG）患者,采用^3H-地塞米松放射配体法测定外周血单个核细胞（PBMC）GR数目, 依据临床相对评分法评价GC治疗后1、6个月疗效,其中24例于GC治疗期间动态观察GR数的变化。结果：治疗前GR数与治疗后1、6个月临床相对评分间呈良好的正相关关系（r＝0．916和r＝0．891,P＜0．01）。治疗前GR数越高,临床相对评分越高,GC疗效越好。GC治疗后GR数降低。结论：用药前测定GR数可以作为预测GC治疗反应、确定治疗方案的一个指标。GC治疗可使GR数下调。     

Is programming of glucocorticoid receptor expression by prenatal dexamethasone in the rat secondary to metabolic derangement in adulthood?

OBJECTIVE: Glucocorticoids may contribute to the association between retarded growth in utero and insulin resistance in adulthood. Administration of dexamethasone (dex) to pregnant rats results in low birth weight offspring, which develop glucose intolerance, hyperinsulinaemia and hypercorticosteronaemia. This may be explained by tIssue-specific differences in expression of glucocorticoid receptors (GR) in adult offspring: GR is increased in visceral fat and liver, and decreased in hippocampus and soleus muscle. However, cause and effect between altered GR expression, hypercorticosteronaemia, and hyperinsulinaemia remains to be established. DESIGN AND METHODS: Rats were treated with dex (100 microg/kg per day) or saline during the third week of pregnancy. In 5-8-Month-old male offspring, GR expression in insulin target tIssues was quantified by RNase protection assay in rats that were adrenalectomised (ADX group), sham operated (SHAM group), or adrenalectomised with supra-physiological corticosterone replacement (CORT group) (n=7-8 per group), and in rats treated orally with vehicle, metformin (43 mg/kg per day) or rosiglitazone (1 mg/kg per day), after 3 weeks. RESULTS: Manipulation of corticosterone concentration did not affect GR mRNA in skeletal muscle or adipose. In liver, sham-operated animals showed lower GR mRNA, but there was no difference between adrenalectomised and hypercorticosteronaemic animals (SHAM 0.11+/-0.01 ratio to beta-actin, vs ADX 0.22+/-0.02, CORT 0.23+/-0.02, (values expressed as means+/-s.e.m.), P<0.001). Rosiglitazone reduced GR mRNA by approximately 30% in liver of dex- and saline-treated offspring (P<0.05), but had no effect on GR in adipose and skeletal muscle. Metformin abolished the 38% up-regulation of liver GR mRNA induced by antenatal dex and also reduced GR mRNA preferentially in muscle of dex-treated animals (0.14+/-0.01 vs 0.10+/-0.01; P=0.03). CONCLUSIONS: We conclude that neither hypercorticosteronaemia nor hyperinsulinaemia are sufficient to cause the changes in GR expression in dex-programmed rats, implying that these changes may be primary in determining the programmed insulin resistant phenotype. Normalisation of GR expression by metformin may be important in the mode of action of this anti-diabetic agent and may be especially useful to reverse-programmed up-regulation of GR.     

Low expression of glucocorticoid receptor alpha isoform in adult immune thrombocytopenia correlates with glucocorticoid resistance

The expression of glucocorticoid receptor (GR) isoforms has been linked to glucocorticoid (GC) resistance in various diseases treated with GC. However, existing data are conflicting in these diseases, and little information is available regarding immune thrombocytopenia (ITP). To further investigate the role of GR isoforms in GC resistance in adult ITP patients, we measured the mRNA expression of GR isoforms (GRα, GRβ, GRγ, GRp) in peripheral blood mononuclear cells (PBMC) from 54 newly diagnosed ITP patients, including GC-sensitive (GCS) and GC-resistant (GCR) patients and 35 healthy volunteers. The GRα and GRβ proteins in PBMC, nuclear factor-κB (NF-κB), and activator protein-1 (AP-1) in the nucleus were detected by Western blotting. Compared to normal subjects, both GRα and GRβ mRNAs were significantly increased in ITP patients (p?<?0.05), while there was no significant difference in the mRNA expression of GRγ and GRp. Compared to GCR patients, the expressions of GRα mRNA and GRα protein were significantly higher in GCS patients (p?<?0.05). Moreover, no significant difference in the mRNA expression of the GRβ, GRγ, and GRp isoforms was observed between GCS and GCR patients and the GRβ protein could not be detected. Compared to GCS group, the expression of p65/NF-κB was significantly higher in the GCR group (p?<?0.05). Overall, we did not find differences in c-Jun/AP-1 protein expression between GCS and GCR patients. In summary, GC resistance in adult ITP patients is associated with a reduced expression of GRα, which may be related with increased NF-κB. GRβ was very low and may not be involved in GC resistance in adult ITP, warranting further exploration.     

Obese Zucker rats have reduced mineralocorticoid receptor and 11beta-hydroxysteroid dehydrogenase type 1 expression in hippocampus-implications for dysregulation of the hypothalamic-pituitary-adrenal axis in obesity

Obese Zucker rats have elevated basal corticosterone levels and an increased stress response suggestive of an increased activity of the hypothalamic-pituitary-adrenal (HPA) axis. We hypothesized that altered central expression of glucocorticoid receptors (GR), mineralocorticoid receptors (MR), and/or 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) contribute to these changes. In brains from young adult male rats, in situ hybridization and Western blotting showed that obese rats had normal hippocampal GR mRNA and protein levels. In contrast, in obese rats, 11betaHSD1 mRNA levels were reduced in a subpopulation of hippocampal cells in the main neuronal layers (by 37-47%, P < 0.05), whereas 11betaHSD1 levels in sparse high-expressing cells did not differ. MR mRNA was decreased in all regions of the hippocampus (by 37-49%, P < 0.05 for CA1-2 and P < 0.01 for dentate gyrus) and in frontal cortex (by 16%, P < 0.05) in obese rats. In whole hippocampal homogenates, however, neither the protein concentration of MR by Western blot nor activity of 11betaHSD1 was measurably different between the phenotypes. To test the functional importance of lower central MR expression, groups of lean and obese rats were given spironolactone before restraint stress. In vehicle-treated animals, obese rats had higher plasma corticosterone levels than lean rats after stress (by ANOVA, P < 0.05). Spironolactone markedly increased the corticosterone response in both groups, but the incremental rise was smaller in the obese rats, so that spironolactone abolished the differences between groups. We conclude that lower levels of MR, but not GR, contribute to the increased HPA activity in the obese Zucker rats and that this seems more influential during stress than in the basal state. This may be exacerbated by impaired local regeneration of corticosterone by 11betaHSD1. These abnormalities could contribute to the subtle changes in the HPA axis in rodent and human obesity.     

糖尿病肥胖大鼠垂体糖皮质激素受体和11β-羟类固醇脱氢酶1 mRNA表达的改变

将大鼠以高脂喂养结合小剂量链脲佐菌素(STZ)诱导,取血测皮质酮和促肾上腺皮质激素(ACTH)的节律后,留取下丘脑和垂体,用实时定量PCR观察下丘脑和垂体糖皮质激素受体和11β-羟类固醇脱氢酶1(11β-HSD1)mRNA表达的改变.对照组、单纯肥胖组和肥胖糖尿病组大鼠的ACTH和皮质酮的水平没有明显改变(P=0.07),但肥胖组和肥胖糖尿病组皮质酮的节律消失.下丘脑糖皮质激素受体mRNA的表达组间无差异,但肥胖糖尿病组11β-HSD1 mRNA的表达高于对照组(P<0.05).垂体糖皮质激素受体和11β-HSD1 mRNA的表达肥胖糖尿病组低于肥胖组,肥胖组又低于对照组(均P<0.05).上述结果提示肥胖伴糖尿病大鼠的负反馈调节机制受损可能与垂体11 β-HSD1和糖皮质激素受体的表达下降有关.     

重症肌无力患者外周血单个核细胞中糖皮质激素受体不同亚型表达和意义

目的探讨重症肌无力（MG）患者外周血单个核细胞（PBMC）中两种糖皮质激素受体（GR）亚型表达水平及其与糖皮质激素疗效的关系。方法在糖皮质激素治疗之前留取MG患者PBMC并涂片,根据糖皮质激素治疗MG的不同疗效分组,通过免疫细胞化学方法观察各组GRα和GRβ阳性细胞比例并评分,分析GRα和GRβ表达量与糖皮质激素疗效的关系。结果对照组、糖皮质激素治疗敏感组和依赖组PBMC中GRα阳性细胞计分差异无统计学意义,3组计分明显高于糖皮质激素治疗抵抗组（P〈0．01）;对照组、糖皮质激素治疗敏感组和糖皮质激素治疗抵抗组PBMC中GRβ计分差异无统计学意义,3组计分明显低于糖皮质激素治疗依赖组（P〈0．01）。结论MG患者PBMC中GRα表达降低和GRβ表达增高均与糖皮质激素疗效降低有关。