高脂饮食诱导胰岛素抵抗小鼠血浆microRNA 表达谱及其与TLR4 的关系

目的:筛选高脂饮食诱导的胰岛素抵抗小鼠,以及应用Toll 样受体4(Toll-like receptor4,TLR4)抑制剂TAK-242 干预的胰岛素抵抗小鼠血浆差异表达的微小RNA(microRNA,miRNA),探讨胰岛素抵抗、TLR4 和差异表达miRNAs 的关系。方法:血浆标本来自前期实验的3 组小鼠,即以普通基础饲料喂养(Low fat diet,LFD)的正常对照组、给予TAK-242 的高脂饮食组(Treated high fat diet,HFD-T)和单纯高脂饮食组HFD-C,应用小鼠miRNA 芯片检测血浆miRNA 表达谱,筛选差异表达的miRNAs;采用实时荧光定量PCR 方法验证芯片结果。应用生物信息学方法,以TLR4 及其信号传导通路为中心,预测差异表达miRNAs 的靶基因,并对靶基因分别进行GO 和KEGG 富集分析,以判定差异miRNAs 主要影响的生物学功能或者通路。结果:miRNA 基因芯片筛查结果显示,单纯高脂饮食组与正常饮食组比对,筛选出差异显著的miRNAs 共计185 种,其中6 种miRNAs 表达上调,179 种miRANs 表达下调;给予TAK-242 的高脂饮食组与正常饮食组比对,筛选出差异显著的miRANs共计171 种,均表达下调;给予TAK-242 的高脂饮食组与单纯高脂饮食组比对,筛选出差异表达的miRNAs 共计13 种,均为下调。生物信息学分析结果显示,以TLR4 为中心挖掘与其互作的蛋白质,共发现有10 种蛋白;在TAK-242 给予的高脂饮食组与单纯高脂饮食组中差异表达倍数均在1 000 以上的4 种miRNAs (mmu-miR-3095-3p、mmu-miR-5113、mmu-miR-709 和mmu-miR-335-3p),可在TLR4 的互作蛋白质或Toll 样受体信号通路中找到其作用的靶基因,发现这些靶基因74% 属于生物过程基因,其中转录调控因子占82%。实时荧光定量PCR 检测mmu-miR-3095-3p、mmu-miR-5113、mmu-miR-709 和mmu-miR鄄335鄄3p水平,变化趋势与芯片结果一致。结论:胰岛素抵抗发生时,血浆miRNAs 表达谱存在改变,此变化与TLR4 及其信号通路相关。该研究结果丰富了胰岛素抵抗发生的机制,为寻找胰岛素抵抗血浆miRNAs 诊断标志物提供了实验依据。     

谷氨酰胺对高脂饮食诱导C57BL/6J小鼠肥胖和胰岛素抵抗的影响

目的:探讨谷氨酰胺(L-glutamine,Gln)对高脂饮食(high-fat diet,HFD)诱导小鼠肥胖和胰岛素抵抗的影响。方法:60只雄性C57BL/6J小鼠随机分为正常对照(normal control,NC)组、HFD组、HFD+丙氨酸(Lalanine,Ala)组和HFD+Gln组,每组15只。每周记录小鼠体重,给药16周后禁食不禁水12 h测定空腹血糖(fasting blood glucose,FBG),处死后剖腹取附睾脂肪垫并称重。采用酶联免疫法检测小鼠胰岛素(insulin,INS)、瘦素(leptin,LEP)、脂联素(adiponectin,APN)和胰高血糖素样肽1(glucagon-like peptide-1,GLP-1)的水平,并计算胰岛素抵抗指数(insulin resistance index,IRI)和胰岛素敏感指数(insulin sensitivity index,ISI)。结果:与NC组比较,HFD组小鼠体重和附睾脂肪垫重量明显升高,FBG、INS、IRI和LEP水平均明显升高,ISI和APN水平明显降低(P0.05);与HFD组比较,HFD+Gln组小鼠体重明显下降,FBG和LEP水平明显降低,IRI明显减小(P0.05)。4组小鼠血清的GLP-1水平差异无统计学显著性。结论:谷氨酰胺减轻高脂饮食诱导的肥胖小鼠体重和胰岛素抵抗。     

小檗碱改善高脂饮食大鼠的胰岛素抵抗

目的:观察小檗碱是否能改善高脂饮食诱导的胰岛素抵抗,以探讨小檗碱干预糖耐量受损(IGT)的可能性。方法:8周龄雄性SD大鼠29只,分为正常组(NC,n=9)和高脂组(HF,n=20)。高脂饲料喂养14周后高脂组分为二组,10只大鼠继续喂养高脂饮食,另一小檗碱组(HF B,n=10)每天灌胃小檗碱150mg/kg体重,治疗6周后进行口服葡萄糖耐量试验和胰岛素耐量试验(ITT),评估小檗碱对胰岛素敏感性的影响。结果:HF组大鼠体重、肝重和附睾脂肪重量均明显高于HF B和NC组(均P<0.01),HF B组空腹血糖和葡萄糖负荷后2h血糖明显低于HF组(分别为5.70±0.52mmol/Lvs6.66±0.51mmol/L和7.88±0.46mmol/Lvs8.85±1.01mmol/L),空腹和葡萄糖负荷后2h胰岛素HF B组也显著低于HF组(分别为0.63±0.25ng/mlvs1.64±0.68ng/ml和1.20±0.21ng/mlvs3.60±0.36ng/ml)。各时间点血糖和胰岛素HF组均显著高于NC组(均P<0.01)。Homa胰岛素抵抗指数HF组明显高于HF B组(P<0.01)。ITT腹腔注射胰岛素后各时间点血糖下降幅度HF B组均高于HF组,15min时HF B组血糖下降23%,而HF组仅下降7%。结论:长期高脂饮食可导致大鼠胰岛素抵抗,小檗碱明显降低高脂大鼠的高胰岛素血症,改善胰岛素抵抗,因此适合于IGT的干预。     

高脂饲养致小鼠胰岛素抵抗对脂肪肝形成的影响

目的:探讨高脂饲养致小鼠脂肪肝形成的机制。方法:随机将8周雄性C57BL/6J小鼠分成高脂饲养组(给予含60%卡路里的高饱和脂肪酸饲养)和正常对照组,饲养12周。监测体重、肝重、血甘油三酯、血总胆固醇、血糖和血胰岛素水平,通过高胰岛素正葡萄糖钳夹实验反映胰岛素敏感性,HE染色、苏丹IV染色及肝脂含量反映肝组织脂质沉积情况,确定高脂饲养致小鼠脂肪肝的形成。通过Western blot法检测磷酸化胰岛素受体底物1(IRS1)和蛋白激酶B(Akt)水平反映胰岛素信号通路激活情况,检测固醇调节元件结合蛋白1(SREBP-1)和脂肪酸合成酶(FAS)蛋白水平反映肝内脂质合成的情况。结果:高脂饲养组小鼠体重及肝重较正常对照组小鼠明显增加。与正常对照组相比,高脂组血和肝组织内甘油三酯和总胆固醇含量显著升高,血清胰岛素水平升高,葡萄糖输注率减少,磷酸化IRS1和Akt水平降低。肝组织HE染色可见高脂组肝细胞胞浆内充满大量脂肪空泡,苏丹IV染色可见肝细胞内存在大量大小不一的红色脂滴;SREBP-1和FAS蛋白水平明显升高。给予外源性油酸干预原代正常肝细胞48 h,磷酸化IRS1和Akt水平呈浓度依赖性减低,而SREBP-1和FAS蛋白表达明显升高。结论:高脂饲养导致小鼠肝脏发生胰岛素抵抗,并通过激活SREBP-FAS脂肪合成途径,促进肝脏脂质沉积,从而诱发脂肪肝。     

氧化苦参碱改善高脂诱导ApoE~(-/-)小鼠的胰岛素抵抗

目的:观察氧化苦参碱对高脂诱导胰岛素抵抗小鼠的作用并初步探讨可能机制。方法:Apo E~(-/-)小鼠高脂喂养16周,分为胰岛素抵抗组以及氧化苦参碱25、50、100 mg/kg组,C57BL/6J小鼠设为对照组,每组10只。灌胃给药8周后,进行小鼠葡萄糖耐量实验;测定血清空腹血糖(FBG)、甘油三酯(TG)、胆固醇(TC)、游离脂肪酸(FFA)和空腹胰岛素(FINS)的含量;实时荧光定量PCR测定肝组织胰岛素受体(INSR)、胰岛素受体底物-2(IRS-2)和葡萄糖转运子2(GLUT_2)的mRNA表达;Western blot法测定肝组织GLUT_2、INSR、IRS-2、p-INSR、p-IRS-2、磷脂酰肌醇3-激酶(PI3K)、p-PI3K、丝氨酸/苏氨酸蛋白激酶(AKT)和p-AKT的蛋白水平。结果:氧化苦参碱能不同程度降低FBG、TG、TC、FFA和FINS水平,改善胰岛素抵抗;氧化苦参碱组INSR、IRS-2和GLUT_2的mRNA表达比胰岛素抵抗组升高(P0.05),p-INSR/INSR、p-IRS-2/IRS-2、p-PI3K/PI3K、p-AKT/AKT和GLUT_2的蛋白水平也升高(P0.05)。结论:氧化苦参碱能通过PI3K/AKT通路,改善高脂诱导小鼠的胰岛素抵抗。     

厚朴酚对高脂饮食性肥胖大鼠体重及胰岛素抵抗的影响

目的 观察厚朴酚对高脂饮食性肥胖大鼠体重和血清生化指标的影响,并探讨其机制.方法 将SD大鼠随机分成4组:对照组,高脂组和厚朴酚高、低二个剂量组.每天定时称量食水、灌胃,每周测体重,第8周末各组大鼠禁食12 hA股动脉取血测定血清生化指标.结果 低剂量厚朴酚组从第4周开始体重比高脂组显著降低(P＜0.05),高、低剂量厚朴酚组的胰岛素、游离脂肪酸、丙二醛以及低剂量组的血糖、三酰甘油比高脂组都显著下降(P＜0.05).结论 厚朴酚能降低高脂饮食性肥胖大鼠的体重,并对胰岛素抵抗和糖脂代谢紊乱等有一定的改善作用.     

高脂饮食诱导肥胖模型大鼠骨骼肌组织蛋白酪氨酸磷酸酯酶1B和胰岛素受体底物2的表达

背景：外周组织的胰岛素抵抗是2型糖尿病的主要病因。 目的：观察高脂饮食诱导的肥胖大鼠骨骼肌中蛋白酪氨酸磷酸酯酶1B和胰岛素受体底物2的表达。 方法：将20只SD大鼠随机等分为对照组和高脂组,分别给予常规饲料和高脂饲料喂养12周。 结果和结论：与对照组相比,高脂组大鼠胰岛素敏感指数显著降低(P < 0.01),大鼠葡萄糖耐量受损,胰岛素释放试验提示葡萄糖刺激的胰岛素第一时相分泌受损,骨骼肌组织中蛋白酪氨酸磷酸酯酶1B蛋白表达水平明显增加(P < 0.01),骨骼肌中胰岛素诱导的胰岛素受体底物2磷酸化程度降低(P < 0.01)。提示高脂饮食诱导的肥胖大鼠骨骼肌中蛋白酪氨酸磷酸酯酶1B蛋白表达量升高,使胰岛素诱导的胰岛素受体底物2磷酸化程度降低,可能是肥胖导致胰岛素抵抗的机制之一。   关键词：肥胖;蛋白酪氨酸磷酸酶1B;胰岛素受体底物2;骨骼肌;胰岛素抵抗 doi:10.3969/j.issn.1673-8225.2012.20.020     

多囊卵巢综合征胰岛素抵抗患者Gly972Arg多态性与子宫内膜胰岛素受体底物1表达的关系

目的:研究多囊卵巢综合征(Polycystic ovary syndrome,PCOS)胰岛素抵抗(Insulin resistance,IR)患者胰岛素受体底物1(Insulin receptor substrate,IRS-1)基因Gly972Arg多态性与子宫内膜IRS-1表达的关系。方法:PCOS患者51例,用聚合酶链反应(PCR)技术,检测IRS-1Gly972Arg多态性。于月经周期第1天刮取子宫内膜,合并胰岛素抵抗者28例,非胰岛素抵抗者23例,应用免疫组化技术检测子宫内膜IRS-1,计算机图像分析系统分析子宫内膜IRS-1的表达。结果:Gly972Arg多态性:51例PCOS患者中,基因型GG 49例,基因型GA 2例,IR组与无IR组各1例,两组比较无统计学意义。子宫内膜IRS-1的表达:IR组、非IR组IRS-1表达的灰度值分别为131.94±18.39、78.16±6.87,比较有统计学意义(P<0.01)。结论:IRS-1Gly972Arg的突变率较低,其多态性在PCOS IR组与无IR组比较无统计学意义(P>0.05),不影响子宫内膜IRS-1的表达。     

高糖、高脂饮食诱导大鼠胰岛素抵抗和血管舒张功能减弱

目的观察高糖、高饱和及高不饱和脂肪酸饮食对大鼠胰岛素抵抗(IR)和血管内皮依赖性舒张功能的影响。方法成年Wistar大鼠随机分为对照组(NC)、高糖组(HS)、高饱和脂肪酸组(HSF)和高不饱和脂肪酸组(HUF),喂养24周后,用正葡萄糖高胰岛素钳夹技术的葡萄糖输注率(GIR)评价IR;用微血管测定技术观察肾动脉累积舒张反应。结果各实验组GIR减低,以HSF组最低,TG、FFA与GIR明显负相关;各实验组大鼠离体肾动脉环对乙酰胆碱(Ach)舒张反应减弱,HSF、HUF和HS组最大舒张反应(Rmax)分别较对照组下降37.4%、32.7%和27.7%;各实验组离体肾动脉环经左旋精氨酸(L-Arg)孵育后对Ach舒张反应增强,经L-NNA、MB孵育后舒张反应减弱;大鼠离体肾动脉环对Ach内皮依赖性舒张反应与TGI、NS明显负相关,与NO、GIR明显正相关,FFA与NO明显负相关。结论高糖、高饱和脂肪酸和高不饱和脂肪酸饮食均可诱导大鼠IR并伴有血管内皮舒张功能减弱。     

替米沙坦对胰岛素抵抗大鼠肾脏脂联素受体1及其mRNA表达的影响

目的探讨替米沙坦对胰岛素抵抗大鼠肾脏脂联素受体1(AdipoR1)及其mRNA表达的影响。方法采用长期高脂喂养建立胰岛素抵抗大鼠模型,并用正常血糖-高血浆胰岛素钳夹技术评估。光镜下行肾脏形态学检查,RT-PCR检测分析AdipoR1 mRNA表达,免疫组化染色观察AdipoR1蛋白水平变化。结果胰岛素抵抗大鼠肾脏AdipoR1 mRNA及其蛋白质表达明显低于正常对照组(均P<0.05),同时大鼠肾脏出现病理变化;替米沙坦干预后,肾组织AdipoR1 mRNA及其蛋白质表达较胰岛素抵抗组升高(P<0.05),同时肾脏病理变化也得到明显改善。结论替米沙坦保护胰岛素抵抗相关的肾脏损伤的作用可能与其调节肾脏AdipoR1的表达相关。     

甜菊糖甙对db/db小鼠胰岛素抵抗和胰岛炎症的影响

目的：大量证据显示,胰岛的炎症反应和胰岛素抵抗是db/db小鼠发生2型糖尿病（DM2）的两个主要因素。甜菊糖甙是一种从菊科植物中提取的天然化合物对于糖尿病病人有许多益处。本实验试图观察甜菊糖甙是否能够改善db/db小鼠的胰岛素抵抗和胰岛炎症反应,从而改善糖代谢。方法：给予db/db小鼠甜菊糖甙或者空白溶剂处理2个月。在处理结束时观察空腹血糖和胰岛素耐量,同时分离胰岛行葡萄糖刺激的胰岛素分泌试验,并行胰腺组织免疫荧光观察胰岛内巨噬细胞浸润情况。结果：甜菊糖甙干预2个月不影响db/db小鼠体重,但显著降低小鼠的空腹血糖,明显改善胰岛素抵抗。同时葡萄糖刺激的胰岛素分泌试验结果提示,甜菊糖甙可显著提高db/db小鼠胰岛在体外分泌胰岛素的能力。此外,免疫荧光提示,甜菊糖甙能显著减轻db/db小鼠胰岛内巨噬细胞浸润程度明显减轻和改善胰岛炎症反应。结论：甜菊糖甙能通过改善胰岛素抵抗和胰岛炎症反应来改善db/db小鼠的糖代谢和胰岛素分泌能力。     

Differential Effects of High-carbohydrate and High-fat Diet Composition on Muscle Insulin Resistance in Rats

This study was conducted to evaluate whether the composition of carbohydrate or fat diet affects insulin resistance by measuring the muscle glucose transport rate. Both high-sucrose and high-starch diet with or without high-fat decreased insulin-stimulated glucose transport, but there were no significant differences among groups. Calorie intake in both high-sucrose and high-starch diet groups was higher than in chow group. The high-fat high-sucrose diet induced decrease in insulin-stimulated glucose transport was partially improved by supplement with fish oil. Calorie intake in high-fat high-sucrose and fish oil supplemented groups was higher than in chow group. The decreased insulin-stimulated glucose transport was accompanied by the increase in visceral fat mass, plasma triglyceride and insulin levels. These changes were improved by the supplement with fish oil. These results demonstrate that the composition of fat in diet is clearly instrumental in the induction of muscle insulin resistance. However, in high carbohydrate diet, it is likely that the amount of calorie intake may be a more important factor in causing insulin resistance than the composition of carbohydrate. Thus, the compositions of carbohydrate and fat in diet differentially affect on muscle insulin resistance.     

自发性2型糖尿病大鼠主动脉形态学改变与胰岛素受体底物1mRNA的表达

目的研究自发性2型糖尿病OLETF大鼠在疾病发展的不同阶段，其主动脉组织形态学改变以及胰岛素受体底物-1（IRS-1）mRNA的表达水平，探讨胰岛素抵抗状态下大血管病变的发生机制。方法10只OLETF大鼠随机分别在16周龄与24周龄检杀，10只同种系非糖尿病LETO大鼠为正常对照组。应用光镜和透射电镜观察大鼠主动脉组织形态学改变，原位杂交技术检测主动脉IRS-1 mRNA表达。结果OLETF大鼠在16周龄时主动脉已出现超微结构异常，至24周时其病变程度加重，表现为典型动脉粥样硬化性早期改变；OLETF大鼠在16周和24周时其主动脉IRS-1 mRNA的表达均明显低于同期LETO对照组，分别减少24．6％（P〈0．01）和25．6％（P〈0．001）。结论血管组织胰岛素受体后信号传递分子在基因转录水平即存在异常，导致内皮细胞胰岛素抵抗，可能是糖尿病早期大血管病变危险性增加的机制之一。     

Intermittent Hypoxia Increases Insulin Resistance in Genetically Obese Mice

Obstructive sleep apnoea, a syndrome that leads to recurrent intermittent hypoxia, is associated with insulin resistance in obese individuals, but the mechanisms underlying this association remain unknown. We utilized a mouse model to examine the effects of intermittent hypoxia on insulin resistance in lean C57BL/6J mice and leptin-deficient obese (C57BL/6J− Lep ^ob) mice. In lean mice, exposure to intermittent hypoxia for 5 days (short term) resulted in a decrease in fasting blood glucose levels (from 173 ± 11 mg dl⁻¹ on day 0 to 138 ± 10 mg dl⁻¹ on day 5, P < 0.01), improvement in glucose tolerance without a change in serum insulin levels and an increase in serum leptin levels in comparison with control (2.6 ± 0.3 vs. 1.7 ± 0.2 ng ml⁻¹, P < 0.05). Microarray mRNA analysis of adipose tissue revealed that leptin was the only upregulated gene affecting glucose uptake. In obese mice, short-term intermittent hypoxia led to a decrease in blood glucose levels accompanied by a 607 ± 136 % (   P < 0.01  ) increase in serum insulin levels. This increase in insulin secretion after 5 days of intermittent hypoxia was completely abolished by prior leptin infusion. Obese mice exposed to intermittent hypoxia for 12 weeks (long term) developed a time-dependent increase in fasting serum insulin levels (from 3.6 ± 1.1 ng ml⁻¹ at baseline to 9.8 ± 1.8 ng ml⁻¹ at week 12, P < 0.001) and worsening glucose tolerance, consistent with an increase in insulin resistance. We conclude that the increase in insulin resistance in response to intermittent hypoxia is dependent on the disruption of leptin pathways.     

Susceptibility and Resistance to Leishmania amazonensis in H-2q Syngeneic High and Low Antibody Responder Mice (Biozzi Mice)

H-2 syngeneic H and L (Biozzi) mice provide a model to study Leishmania infections in which polar resistant and susceptible phenotypes are independent from H-2 differences. High-Ab-responder (H) and low-Ab-responder (L) mice syngeneic at the H-2 locus (H-2^q) were, respectively, susceptible and highly resistant to Leishmania amazonensis infection. L-mice resistance was associated with high IFN-γ and transient IL-4 production by lymph node (LN) cells, in contrast with sustained IL-4 and decreasing IFN-γ production by susceptible H mice. IL-12 production could be detected only in LN from resistant mice. The cytokine production pattern was consistent with preferential progression to a Th1-type response in resistant L-mice, and to a Th2-type response in susceptible H-mice. We also investigated whether this shift towards Th1- or Th2-type cytokine responses was dependent upon H or L antigen presenting cells' (APC) intrinsic ability to preferentially stimulate either T-cell subset. To this end, LN-derived T-cell lines were grown from 12-day infected mice, when both strains produced IFN-γ and IL-4. L-derived T-cell lines developed a Th2 cytokine pattern whereas H-derived T-cell lines produced IFN-γ, IL-4 and IL-10 whatever the APC origin (H or L) used for their derivation. This work constitutes the first characterization of cellular immune responses to the intracellular parasite, L. amazonensis in H-2 syngeneic mice, an infection model in which polar resistant and susceptible phenotypes are determined by non-MHC genes.     

老年小鼠对肺炎双球菌多糖抗原低带耐受的抵抗性

20月龄BALB/c小鼠对最适免疫剂量的PPS-3的免疫应答明显高于青年成鼠(P<0.001),对PPS-14的二次应答,特别是IgG抗体水平与青年成鼠相比P<0.001。低剂量PPS可诱导小鼠免疫耐受。老年小鼠对PPS-3的免疫应答不受低剂量PPS-3前处理的影响。它们对PPS-3低带耐受的抵抗性与裸鼠相同,对PPS-14低带耐受的抵抗性主要表现在二次免疫应答中。老年鼠对PPS的免疫应答及低剂量PPS诱导免疫耐受的反应不同于青年成鼠,可能是老年鼠Ts细胞功能减退所致。     

不同方式注射TNFα对正常小鼠胰岛素抵抗的影响

肿瘤坏死因子a（TNFa）是由单枚巨噬细胞系统分泌的一种多方面生物活性的细胞因子。它不仅介导肿瘤细胞溶解，且在物质和能量代谢中也发挥重要作用。本文以空腹血糖胰岛乘积（EGI）作为胰岛素抵抗的定量指标，通过对正常小鼠多种方式静脉注射TNFa，以比较观察TNFa对糖代谢的改变和胰岛素抵抗的发生的影响。材料与方法：TNFa由军事医学科学院提供，用5％BSA溶液配制。昆明小鼠（22～259），雌雄不拘，随机分为低剂量IHg／（kg·h）连续注射织间隔30min一次、高剂量100pg／（kg·h）连续注射组间隔30min一次，和高剂量200pg／（kg’h…     

Reduction of insulin signalling pathway IRS-1/IRS-2/AKT/mTOR and decrease of epithelial cell proliferation in the prostate of glucocorticoid-treated rats

Previous studies by our research group using a model of insulin resistance induced by dexamethasone (DEX) showed that in the rat ventral prostate there was epithelial and smooth muscle cell atrophy and there were also alterations in fibroblasts. Proteins of the insulin signalling pathway are known to be very important for cell proliferation and development. Thus, we investigated the insulin signalling pathway and epithelial proliferation in the rat ventral prostate in this model and correlated the findings with expression of glucocorticoid (GR) and androgen (AR) receptors. Insulin resistance was induced in adult male Wistar rats by injection of DEX (1 mg/kg, ip for 5 consecutive days), whereas control (CTL) rats received saline. DEX treatment resulted in a significant decrease in body weight, but not in prostate weight. Reductions in insulin receptor 1 (IRS-1) (CTL 1.11 ± 0.06; DEX 0.85 ± 0.03), IRS-2 (CTL 0.95 ± 0.05; DEX 0.49 ± 0.04), AKT (CTL 0.98 ± 0.03; DEX 0.78 ± 0.02), mammalian target of rapamycin (mTOR; CTL 0.65 ± 0.08; DEX 0.22 ± 0.05), GR (CTL 1.30 ± 0.09; DEX 0.57 ± 0.10) and AR (CTL 1.83 ± 0.16; DEX 0.55 ± 0.08) protein levels were observed in the prostate of DEX-treated rats. The expression of the IRα-subunit, phosphoinositide 3-kinase, p-AKT, p70(S6K) , extracellular signal-regulated kinase (ERK) and p-ERK was not altered. The frequency of AR-positive cells in the epithelium of the prostate decreased in the glucocorticoid-treated group, and the intensity of the reaction for this receptor in the cell nuclei was lower in this group. Furthermore, the treatment with DEX reduced the frequency of proliferating cell nuclear antigen-positive (PCNA) cells 30-fold. This study suggests that the reduction in the insulin signalling pathway proteins IRS-1/IRS-2/AKT/mTOR in the prostate of DEX-treated rats may be associated with the morphological alterations observed previously.