链脲佐菌素诱导的糖尿病大鼠外周血白细胞iNOS-mRNA表达的变化

目的：研究链脲佐菌素（STZ）诱导的糖尿病大鼠胰岛β细胞的功能与外周血白细胞iNOS-mRNA表达的关系。方法：Wistar大鼠随机分为对照10只,实验15只。测定血糖、血浆胰岛素;用原位杂交方法检测外周血白细胞、肝、肺等组织中iNOS-mRNA表达,观察白细胞iNOS-mRNA阳性细胞率。结果：用STZ腹腔注射损伤胰岛β细胞并导致胰岛功能衰竭,3 d后血糖由(8.95±1.80) mmol·L^-1升高至(22.84±4.90) mmol·L^-1,血浆胰岛素由(81.76±2.12) mU·L^-1降至(58.92±18.20)mU·L^-1。正常大鼠外周血白细胞未见iNOS-mRNA表达,而STZ诱导的糖尿病大鼠外周血白细胞iNOS-mRNA表达高度增强。结论：STZ诱导的胰岛β细胞损伤与白细胞的iNOS-mRNA表达存在正相关关系。本实验为检测外周血白细胞某些信号通路提供了简便易行的原位杂交试验方法。     

链脲佐菌素诱导MSG大鼠糖尿病心脏病模型的研究

目的:探讨腹腔注射链脲佐菌素(Streptozotocin,STZ)诱导L-谷氨酸钠(Monosodium glutamate,MSG)肥胖大鼠建立糖尿病心脏病模型。方法:选用新生SD大鼠随机分为两组:MSG组和正常对照组(NS组)。MSG组新生大鼠自出生第2d起颈部皮下注射L-谷氨酸钠5g·kg-1,隔天一次,共三次;正常对照组于皮下注射等体积无菌注射用水。MSG组于6周龄时再随机分为4个小组,腹腔注射链脲佐菌素0mg·kg-1,20mg·kg-1,30mg·kg-1,40mg·kg-1。于注射STZ 4w后测定各心脏血流动力学相关指标,同时取血测定其胰岛素水平及血液脂质等指标。结果:注射STZ 4w后,MSG组大鼠Lee’s指数显著增加,心脏指数明显降低,血浆高密度胆固醇(HDL)、低密度胆固醇(LDL)升高,收缩压(SBP)、舒张压(DBP)、平均动脉压(MAP)、心率(HR)、左心室收缩压(LVSP)、左心室内压最大上升速率(+dp/dt)、下降速率(-dp/dt)均显著升高,心电图显示其Q-T间期缩短,与对照组比较有统计学差异。MSG+STZ 30mg·kg-1组大鼠SBP、DBP、MAP、HR、+dp/dt、-dp/dt均显著降低,与MSG组比较有统计学差异。MSG+STZ 40mg·kg-1组大鼠SBP、DBP、MAP、HR、LVSP、+dp/dt、-dp/dt均显著降低,Lee’s指数降低,胰岛素浓度降低,血糖水平及心脏指数升高,血浆LDL水平降低,Q-T间期延长,与MSG组比较有统计学差异。结论:研究表明MSG大鼠在6周龄时腹腔注射STZ 40mg·kg-1,有利于糖尿病心脏病模型的建立,为研究、开发防治2型糖尿病心脏病的新药提供了一种良好的动物模型。     

链尿佐菌素制备糖尿病神经源性膀胱大鼠模型

目的对使用单次腹腔注射大剂量链尿佐菌素（STZ）制备糖尿病神经源性膀胱大鼠模型的方法进行探讨。方法使用随机分组的方法将30只SPF级健康雄性sD大鼠随机分成正常对照组（NC组）10只、糖尿病组（DM组）20只;给予糖尿病组大鼠单次腹腔注射链尿佐菌素（60mg／kg）,同时给予对照组大鼠相同剂量的柠檬酸钠缓冲液,3d后测空腹血糖,血糖≥16．7mmol／L大鼠入选为糖尿病组模型。后观察大鼠一般指标（精神、皮毛光泽度、血糖、体重、饮食量、饮水量等）,8周时取出膀胱测残尿量、膀胱湿重、行HE染色。结果3d后糖尿病组大鼠糖尿病成模率达到90％,8周后血糖值稳定,糖尿病组膀胱HE染色有明显病理改变。DM组中糖尿病大鼠模型的糖尿病神经源性膀胱大鼠模型成模率为100％。结论通过单次大剂量腹腔注射链尿佐菌素（60mg／kg）可快速制备稳定的糖尿病大鼠模型,且在此基础上诱导神经源性膀胱大鼠模型的成功率高,在8周时其成模率可达100％。是目前一种简便、快速获取稳定糖尿病神经源性性膀胱大鼠模型的方法。     

链脲佐菌素诱导的糖尿病大鼠外周血白细胞iNOS—mRNA表达的变化

目的 :研究链脲佐菌素 (STZ)诱导的糖尿病大鼠胰岛 β细胞的功能与外周血白细胞iNOS -mRNA表达的关系。方法 :Wistar大鼠随机分为对照组 10只 ;实验组 15只。测定血糖、血浆胰岛素 ;用原位杂交方法检测外周血白细胞、肝、肺等组织中iNOS -mRNA表达 ,观察白细胞iNOS -mRNA阳性细胞率。结果 :用STZ腹腔注射损伤胰岛β细胞并导致胰岛功能衰竭 ,3d后血糖由 ( 8 95± 1 80 )mmol·L-1升高至 ( 2 2 84± 4 90 )mmol·L-1,血浆胰岛素由 ( 81 76± 2 0 12 )mU·L-1降至 ( 5 8 92± 18 2 0 )mU·/L-1。正常大鼠外周血白细胞未见iNOS -mRNA表达 ,而STZ诱导的糖尿病大鼠外周血白细胞iNOS -mRNA表达高度增强。结论 :STZ诱导的胰岛 β细胞损伤与白细胞的iNOS -mRNA表达存在正相关关系。本实验为检测外周血白细胞某些信号通路提供了简便易行的原位杂交试验方法。     

TRPV1阻断剂的研究进展

瞬时感受器电位香草酸受体1(TRPV1)是瞬时感受器电位（transient receptor potential,TRP)的非选择性阳离子通道蛋白家族成员之一，主要表达在初级传入感觉神经元上，是一种非选择性的阳离子通道。该受体可探测和整合诱发痛觉的化学和热刺激信号，主要有辣椒素（红辣椒的辛辣成分），伤害性热（>43℃）和质子等。它可将化学、机械和热刺激信号转化为动作电位，并将这些信息上传到中枢，最后使机体产生痛觉或不舒服的感受。近年来，TRPV1通道蛋白已成为开发新的镇痛药物的重要靶点。     

Neuregulin-1在糖尿病大鼠心肌组织中的表达变化

目的: 探讨neuregulin-1(NRG-1)在糖尿病大鼠心肌组织中的表达。方法: 45只雄性SD大鼠随机分为4周、8周和12周糖尿病组(4th、8th 和12th DM组),4周、8周和12周对照组(4th 、8th 和12th C组)。腹腔注射链脲佐菌素诱导糖尿病模型。在诱导糖尿病后第4、8和12周用超声诊断仪评估大鼠心功能,计算心肌胶原容积分数(CVF),免疫组化观察NRG-1在心肌的表达部位,RT-PCR和Western blotting检测NRG-1 mRNA及蛋白的表达水平。结果: 4th DM组大鼠心功能指标、心肌CVF、NRG-1 mRNA及蛋白的表达与4thC组相比,差异无统计学意义(P>0.05);与8th C组相比,8th DM组左室收缩末内径(LVESD)和心肌CVF均增高,但左室短轴缩短率(LVFS)、左室射血分数(LVEF)、心肌NRG-1 mRNA及蛋白的表达仍未见明显改变(P>0.05)。与12th C组比较,12th DM组LVESD和心肌CVF均显著增高,而LVFS和LVEF显著降低(均P<0.01)。12th DM组心肌NRG-1 mRNA及蛋白的表达较同期对照组显著下调(0.073±0.008 vs 0.156±0.010,0.171±0.054 vs 0.324±0.039,均P<0.01)。结论: NRG-1在糖尿病大鼠心肌组织中的表达显著下调,这可能参与了糖尿病心肌病的发生和发展。     

链脲佐菌素诱导的糖尿病早期小鼠胸主动脉钾通道变化

目的:探讨链脲佐菌素诱导的糖尿病早期小鼠胸主动脉钾通道的变化。方法:实验采用离体血管的方法测定糖尿病鼠和正常鼠胸主动脉环对血管收缩剂:60mmol/LKCl和苯肾上腺素(PE)、内皮非依赖性舒张剂:硝普钠(SNP)以及电压依赖性钾通道(K_V通道),钙激活型钾通道(K_Ca通道),ATP敏感钾通道(K_ATP通道)阻断剂的反应。结果:糖尿病鼠胸主动脉环对60mmol/LKCl、PE和SNP的效应都显著大于对照组;K_Ca通道阻断剂四乙铵(TEA)显著降低糖尿病小鼠胸主动脉环在PE的激动下SNP的舒张效应,而且其-logIC₅₀的差值较对照组显著增大;K_V通道阻断剂4-氨基吡啶(4-AP)显著降低糖尿病和正常小鼠胸主动脉环对SNP的舒张效应,但是-logIC₅₀差值无显著差异;K_ATP通道阻断剂格列苯脲(Glibenclamide)显著降低糖尿病小鼠胸主动脉环对SNP的舒张效应,而对照组无显著阻断作用,-logIC₅₀的差值也无显著差异。结论:糖尿病早期小鼠胸主动脉平滑肌细胞K_Ca通道的开放或表达显著增强,也证实了K_ATP通道开放增强。     

伊贝沙坦对链脲佐菌素诱导的糖尿病大鼠肾脏肥大的影响

目的:探讨新型血管紧张素II受体拮抗剂伊贝沙坦(Irb)对链脲佐菌素(STZ)诱导的糖尿病大鼠肾脏肥大的影响。方法:SD大鼠随机分为3组:正常对照组(N组,n=7),糖尿病肾病组(DN组,n=6)和伊贝沙坦治疗组(DNI组,n=7)。大鼠单侧肾切除后,腹腔注射STZ诱导糖尿病模型。于第4、8、12周分别测血糖(BG)、体重(BW)、尿白蛋白排泄(Ualb)、24h尿蛋白(24hUpro)定量,12周实验结束时测肌酐清除率(Ccr)、肾重(KW)、肾脏肥大指数(KW/BW)、肾组织总蛋白含量(RTP)、肾小球面积(A_G)和体积(V_G)、肾小球毛细血管基底膜(GBM)厚度等改变。结果:DN组和DNI组间BG差异无显著(P>0.05)。Irb可明显降低糖尿病大鼠Ualb、24hUpro排泄,抑制Ccr的增高(P＜0.01);Irb可显著抑制糖尿病大鼠KW、KW/BW、RTP、A_G、V_G的增加(P＜0.05或P＜0.01)和GBM的增厚(均为P＜0.01)。结论:糖尿病大鼠早期应用Irb可减轻尿蛋白排泄,并通过抑制肾脏肥大和GBM增厚而发挥肾保护作用。     

海马sortilin在链脲佐菌素诱导的糖尿病认知损伤小鼠中的作用

目的 探讨海马sortilin在链脲佐菌素（STZ）诱导的糖尿病认知损伤小鼠中的作用。方法 24只成年雄性ICR小鼠,随机分为溶媒对照组（NS）和实验组（STZ）。STZ腹腔注射诱导糖尿病认知损伤动物模型,注射后用血糖仪检测血糖改变,注射后第8周采用新旧事物识别实验检测各组小鼠认知功能;免疫组织化学方法检测sortilin免疫阳性产物表达变化;Western blotting和Real-time PCR方法检测各组小鼠海马sortilin和脑源性神经营养因子（BDNF）蛋白及mRNA表达变化。结果 与NS组相比,STZ组小鼠空腹血糖显著增高（P<0.01）;在新旧事物识别实验中新事物辨别指数明显降低（P<0.05）;海马区sortilin的免疫阳性产物（P<0.05）、蛋白（P<0.01）以及mRNA（P<0.05）表达均显著下调;海马区BDNF mRNA（P<0.01）及蛋白（P<0.05）表达均明显降低。结论 STZ诱导的糖尿病小鼠认知损伤可能与海马sortilin的表达下调有关。     

链脲佐菌素敏感的胰岛细胞表达亨廷顿蛋白相关蛋白1

目的探讨亨廷顿蛋白相关蛋白1（HAP1）在大鼠胰岛中的定位.方法应用一次性大剂量腹腔注射链脲佐菌素（streptozotocin）的方法选择性破坏大鼠胰岛B细胞复制糖尿病模型,免疫组织化学ABC法显示胰岛内HAP1和胰岛素免疫反应性.结果在正常大鼠胰腺内,HAP1选择性表达于胰岛内,HAP1免疫反应阳性细胞呈短条索状或团状分布在每个胰岛内,主要位于胰岛的中央部,与胰岛B细胞的分布十分相似.注射链脲佐菌素的大鼠,胰岛中含HAP1的细胞数量在注射链脲佐菌素3d后已明显减少,并随着注射后动物存活时间的延长而进一步进行性减少;在注射后4周的大鼠,胰岛中仅有少数散在分布的HAP1免疫反应弱阳性细胞.链脲佐菌素对胰岛中表达HAP1细胞的影响与对表达胰岛素细胞的影响一致.结论HAP1也存在于胰岛内,并主要定位于链脲佐菌素敏感的B细胞内.     

Altered urinary bladder function in mice lacking the vanilloid receptor TRPV1

In the urinary bladder, the capsaicin-gated ion channel TRPV1 is expressed both within afferent nerve terminals and within the epithelial cells that line the bladder lumen. To determine the significance of this expression pattern, we analyzed bladder function in mice lacking TRPV1. Compared with wild-type littermates, trpv1(-/-) mice had a higher frequency of low-amplitude, non-voiding bladder contractions. This alteration was accompanied by reductions in both spinal cord signaling and reflex voiding during bladder filling (under anesthesia). In vitro, stretch-evoked ATP release and membrane capacitance changes were diminished in bladders excised from trpv1(-/-) mice, as was hypoosmolality-evoked ATP release from cultured trpv1(-/-) urothelial cells. These findings indicate that TRPV1 participates in normal bladder function and is essential for normal mechanically evoked purinergic signaling by the urothelium.     

STZ诱导糖尿病大鼠肾脏CTGF表达改变及意义探讨

目的：观察STZ诱导糖尿病大鼠肾脏结缔组织生长因子(CTGF)表达改变及意义。方法:将SD大鼠分为对照(假手术)组(C组)（n=32）、糖尿病肾病组(DN组)（n=35）2组。每组再随机分为4个亚组：1周、2周、4周和8周组。观察各组大鼠血糖（BG）、24 h尿量（UV）、体重（BW）、尿白蛋白排泄(24 Ualb)、内生肌酐清除率(Ccr)、肾重(KW)、肾重/体重(KW/BW)、肾小球面积(A_G)和体积(V_G)、近端小管面积(A_T)、GBM、TBM厚度的改变，免疫组化观察CTGF和α-SMA在小球、小管的表达情况。结果：实验期间DN组BG、UV明显大于C组（P<0.01），DN组24 h Ualb（mg/24 h）、Ccr、KW、 KW/BW、A_G、V_G、A_T、小球及小管的CTGF表达均持续显著高于C组，AT在4周时达到高峰，且CTGF表达与24 Ualb、A_G、V_G、A_T等指标呈显著正相关 (r分别=0.95、0.92、0.86、0.94, 分别P<0.01、 P<0.05)。α-SMA 在DN组大鼠早期肾小管上皮细胞中表达不明显，第4周起可见少量α-平滑肌肌动蛋白(α-SMA)表达，到第8周时更明显。8周时DN组GBM和TBM明显厚于C组 (P<0.01)。结论：糖尿病早期CTGF表达增加，并可能参与介导糖尿病早期肾脏肥大，CTGF可能与随后的肾小管上皮细胞转分化和肾脏纤维化有关。     

实时FQ-PCR检测链脲佐菌素诱导糖尿病小鼠模型胰腺survivin基因的表达

目的：研究链脲佐菌素（STZ）诱导的糖尿病小鼠胰腺survivin基因mRNA表达，了解其在胰岛损伤中的作用。 方法： 小剂量多次注射STZ的方法建立糖尿病小鼠模型，每周测定体重及血糖，并采用实时荧光PCR方法检测胰腺survivin基因mRNA表达水平。 结果： 正常BALB/c小鼠胰腺有survivin基因表达。STZ组体重在4周内无明显改变；血糖在第1周即明显升高；survivin表达水平在3、4周显著升高。对照组体重持续增加，血糖及survivin表达水平各周间无显著差异。 结论： 正常小鼠胰腺有survivin基因表达，STZ注射后survivin表达水平显著升高，可能与胰岛恢复有关。     

MaxiK channel-triggered negative feedback system is preserved in the urinary bladder smooth muscle from streptozotocin-induced diabetic rats.

MaxiK channel, the large-conductance Ca2+-sensitive K+ channel, facilitates a negative feedback mechanism to oppose excitation and contraction in various types of smooth muscles including urinary bladder smooth muscle (UBSM). In this study, we investigated how the contribution of MaxiK channel to the regulation of basal UBSM mechanical activity is altered in streptozotocin-induced diabetic rats. Although the urinary bladder preparations from both control and diabetic rats were almost quiescent in their basal mechanical activities, they generated spontaneous rhythmic contractions in response to a MaxiK channel blocker, iberiotoxin (IbTx). The effect of IbTx on the mechanical activity was significantly greater in diabetic rat than in control animal. Similarly, the basal mechanical activity was increased with apamin, an inhibitor for some types of small conductance Ca2+-sensitive K+ channels, and this effect was more pronounced for diabetic rat. However, in both control and diabetic animals, IbTx action was stronger than that of apamin. Diabetes also enhanced the responses to BayK 8644, an L-type Ca2+ channel agonist. The extent of this enhancement in diabetic bladder vs. control was, however, almost the same as that attained with IbTx. Expression levels for MaxiK channel as well as apamin-sensitive K+ channels and L-type Ca2+ channel were not altered by diabetes, when determined as their corresponding mRNA levels. These results indicate that diabetes can potentially increase the basal UBSM mechanical activity. However, in diabetic UBSM, the main negative-feedback system triggered by MaxiK channel is still preserved enough to counteract the possible enhancement of this smooth muscle mechanical activity.     

Alpha-lipoic Acid modulates heat shock factor-1 expression in streptozotocin-induced diabetic rat kidney

Increased oxidative stress and impaired heat shock protein (HSP) synthesis may contribute to diabetic nephropathy. The question of whether 8-week thiol antioxidant alpha-lipoic acid (LA) supplementation modulates HSP response and oxidative stress was studied in the kidney of streptozotocin-induced diabetic (SID) and nondiabetic rats. SID caused a histological mesangial expansion, tubular dilatation, and increased levels of transforming growth factor-beta (TGF-beta), a mediator of glomerulosclerosis. SID increased 4-hydroxynonenal (4-HNE) protein adduct formation, a marker of lipid peroxidation, and heme oxygenase-1 (HO-1), also a marker of oxidative stress. Moreover, SID increased the DNA-binding activity of heat shock factor-1 (HSF-1) and expression of heat shock protein 60 (HSP60). In contrast, LA supplementation partially reversed histological findings of glomerulosclerosis and decreased TGF-beta. LA also increased HSF-1 and decreased HO-1 protein expression, without affecting 4-HNE protein adduct levels. At the mRNA level, LA increased expression of HSF-1, HSP90, and glucose-regulated protein (GRP75) in both control and diabetic animals and HSP72 in SID rats. However, LA supplementation did not affect these HSPs at the protein level. These findings suggest that in addition to its antiglomerulosclerotic effects, LA can induce cytoprotective response in SID.     

Expression and function of bradykinin B1 and B2 receptors in normal and inflamed rat urinary bladder urothelium

The bladder urothelium exhibits dynamic sensory properties that adapt to changes in the local environment. These studies investigated the localization and function of bradykinin receptor subtypes B1 and B2 in the normal and inflamed (cyclophosphamide (CYP)-induced cystitis) bladder urothelium and their contribution to lower urinary tract function in the rat. Our findings indicate that the bradykinin 2 receptor (B2R) but not the bradykinin 1 receptor (B1R) is expressed in control bladder urothelium. B2R immunoreactivity was localized throughout the bladder, including the urothelium and detrusor smooth muscle. Bradykinin-evoked activation of this receptor elevated intracellular calcium  (EC₅₀= 8.4 n m )  in a concentration-related manner and evoked ATP release from control cultured rat urothelial cells. In contrast, B1R mRNA was not detected in control rat urinary bladder; however, following acute (24 h) and chronic (8 day) CYP-induced cystitis in the rat, B1R mRNA was detected throughout the bladder. Functional B1Rs were demonstrated by evoking ATP release and increases in [Ca²⁺]_i in CYP (24 h)-treated cultured rat urothelial cells with a selective B1 receptor agonist (des-Arg⁹-bradykinin). Cystometry performed on control anaesthetized rats revealed that intravesical instillation of bradykinin activated the micturition pathway. Attenuation of this response by the P2 receptor antagonist PPADS suggests that bradykinin-induced micturition facilitation may be due in part to increased purinergic responsiveness. CYP (24 h)-treated rats demonstrated bladder hyperactivity that was significantly reduced by intravesical administration of either B1 (des-Arg¹⁰-Hoe-140) or B2 (Hoe-140) receptor antagonists. These studies demonstrate that urothelial expression of bradykinin receptors is plastic and is altered by pathology.     

Effects of neonatal capsaicin treatment and streptozotocin-induced diabetes on urinary bladder function in rats

A significant increase in the size and weight of the urinary bladder was observed 2 weeks after streptozotocin treatment and 2 months after neonatal capsaicin treatment. Both treatments induced a significant increase in the level of [³H]quinuclidinyl benzilate binding to muscarinic cholinergic receptors in the urinary bladder membranes. However, contractile responses of urinary bladder muscle strips to carbachol (0.3–20 μM) were not significantly affected by either treatment. On the other hand, neonatal capsaicin treatment, but not streptozotocin treatment, significantly enhanced contractile responses of bladder strips to electric field stimulation.     

Participation of TRPV1 and TRPV2 in the rat laryngeal sensory innervation

Laryngeal sensory innervation is essential to the laryngeal defense system. We investigated the participation of TRPV1 and its homologue TRPV2 in the rat laryngeal sensory innervation using immunohistochemistry and the neuronal tracer, fluoro-gold (FG). After injection of FG into the internal branch of the superior laryngeal nerve, FG-labeled neurons were seen in the rostral part of the nodose ganglion (NG). Neurons immunoreactive for TRPV1 or TRPV2 were distributed throughout the NG. TRPV1 immunoreactivity was seen in 49.0+/-4.5% of the FG-labeled neurons, while TRPV2 immunoreactivity was seen in 12.5+/-4.1% of the FG-labeled neurons. These findings suggest that both TRPV1 and TRPV2 participate in laryngeal nociception, but that TRPV1 may have a particularly important role.