Hypertrophy and reversal of hypertrophy in rat pelvic ganglion neurons

Summary An experimental procedure which chronically reduces the lumen of the urethra in adult female rats produced distension of the bladder and conspicuous thickening of its wall, resulting within 6–8 weeks in a ten-fold increase in muscle weight (muscle hypertrophy). During this process, the neurons in the pelvic ganglion that innervate the bladder undergo a large increase in size (neuronal hypertrophy). The average neuronal volume increased by 83%; small neurons became less numerous and large neurons became more numerous than in controls, but there was no increase in the maximum neuronal size. Six weeks after re-operation and removal of the urethral obstruction, the weight of the bladder was reduced (although not quite to the control levels), while the average neuronal size reversed to values very close to controls.In separate experiments, the pelvic ganglion of one side was removed. The nerve fibres in the hemidenervated bladder sprouted, grew and spread to innervate the whole bladder. The neurons in the surviving pelvic ganglion hypertrophied, the average cell volume increasing by 50% in seven weeks.The experiments showed that: (i) the pelvic neurons of adult rats are capable of very extensive growth when the tissue they innervate (bladder muscle) undergoes hypertrophy; (ii) the neuronal hypertrophy is reversible. This was taken to imply that there are factors within the bladder, including trophic substances, that regulate nerve cell volume not only by inducing growth but also by inducing the opposite effect, a cell size reduction; (iii) unilateral ganglionectomy, which did not induce muscle hypertrophy but doubled the amount of muscle innervated by the contralateral ganglion, was followed by marked neuronal hypertrophy.     

Assessment of Intramural Blood Flow and Neurogenic Control in Intact and Hypertrophic Urinary Bladder with Harmonic Analysis of Bioimpedance in Rats

High-resolution impedancometry and harmonic (Fourier) analysis of variable component of bioimpedance revealed rhythmic oscillations of urinary bladder bioimpedance at the Mayer wave, respiration, and heartbeat frequencies. The power values of the corresponding Mayer, respiratory, and cardiac peaks were calculated to assess circulation in the urinary bladder wall and its autonomic nervous control at various stages of infusion cystometry in intact rats and in the rats with preliminary formed infravesical obstruction (IVO). In intact rats, filling of the bladder with physiological saline diminished the power of the first (fundamental) cardiac peak attesting to a decrease of the blood flow in the bladder wall. Simultaneously, the power of low-frequency Mayer peak reflecting sympathetic activity increased, while the power of respiratory peak decreased supposedly reflecting abatement of the parasympathetic influences. Bladder voiding was accompanied by a decrease of Mayer peak and increase of the respiratory one. Prior to infusion cystometry, the intravesical pressure in IVO rats was elevated while the power of fundamental cardiac peak was below the control value. Filling the bladder in these rats was accompanied by further decrease of the cardiac peak reflecting still greater drop in blood supply. In control rats, voiding the bladder normalized the vesical circulation assessed by the cardiac peak, while in IVO rats this peak remained decreased. The reciprocal changes of Mayer and respiratory peaks observed during infusion cystometry in the norm were replaced by unidirectional decrease in the power of both peaks in IVO rats, which probably attest to disturbance of autonomic nervous control in the hypertrophic urinary bladder in these rats.     

低剂量紫杉醇对膀胱出口部分梗阻后膀胱形态变化的影响

 目的:探讨低剂量紫杉醇对膀胱出口部分梗阻（BOO）大鼠膀胱形态变化的影响。方法:健康雌性Sprague-Dawley大鼠30只,随机分为空白对照组、BOO组和紫杉醇组。BOO组和紫杉醇组行尿道近端梗阻方式制备膀胱出口部分梗阻模型,空白对照组采用假手术方式处理。紫杉醇组于术后给予紫杉醇(溶于生理盐水)腹腔注射（0.3 mg/kg）,每周2次。空白对照组与BOO组以等体积生理盐水同时间腹腔注射。4周后测量体重及膀胱重量,HE染色观察膀胱肌层增生情况;Masson三色染色观察并评价胶原纤维沉积;透射电镜观察逼尿肌超微结构改变。结果:与空白对照组相比,BOO组膀胱重量明显增加（0.376 g±0.052 g vs0.112 g±0.014 g, P<0.05）,膀胱逼尿肌明显增厚,胶原纤维面积占胶原与肌组织面积之和的比值下降（29.66％±2.69％ vs38.94％±3.67％, P<0.05）,电镜下细胞中间连接明显减少,出现丰富的突触连接与桥粒连接,肌细胞间隙内有大量的胶原纤维。与BOO组相比,紫杉醇组膀胱重量显著降低（0.215 g±0.025 g vs0.376 g±0.052 g, P<0.05）,膀胱逼尿肌厚度减小,胶原纤维染色面积占胶原与肌组织面积之和的比值下降（19.94%±1.90% vs29.66%±2.69%, P<0.05）,细胞间连接以中间连接为主,细胞间隙内胶原纤维减少。结论: 低剂量紫杉醇对BOO后膀胱形态结构的变化有一定的修复或逆转作用。     

纤维连接蛋白在肾间质纤维化大鼠肾组织中的表达

背景：纤维连接蛋白表达增加在肾间质纤维化疾病进展过程中发挥着的重要作用。 目的：观察纤维连接蛋白在肾间质纤维化大鼠肾组织中的表达。 方法：72只大鼠随机等分为对照组、假手术组和模型组。模型组建立单侧输尿管梗阻模型;假手术组仅开腹游离左侧输尿管;对照组不做任何处理。 结果与结论：与对照组及假手术组比较,模型组大鼠梗阻时间越长,肾小管间质损害程度越重,纤维化越明显,肾组织中纤维连接蛋白、基质金属蛋白酶9和转化生长因子β1表达即明显增多,且随着梗阻时间延长,肾组织中纤维连接蛋白、基质金属蛋白酶9和转化生长因子β1表达呈持续增加趋势,至造模后第14天达到高峰,与同期对照组、假手术组相比差异有显著性意义(P < 0.01),说明在大鼠肾纤维化形成过程中,纤维连接蛋白的蛋白表达在肾损伤早期即显著增加,并随肾间质纤维化程度加重而逐步升高,从而促进肾纤维化的发生。而基质金属蛋白酶9的高表达可能是加重肾间质损害的因素之一。     

E-钙黏蛋白在单侧输尿管梗阻模型大鼠肾间质纤维化中的作用

背景：细胞黏附的丧失及E-钙黏蛋白表达下降在肾小管上皮细胞转分化导致肾间质纤维化疾病进展过程中发挥着的重要作用。 目的：观察单侧输尿管梗阻模型大鼠肾小管间质纤维化动态及该病理过程中E-钙黏蛋白、整合素连接激酶蛋白的表达,探讨E-钙黏蛋白在肾小管间质纤维化中的作用机制。 方法：72只SD大鼠随机摸球法均分为正常组、对照组和模型组。模型组建立单侧输尿管梗阻模型;对照组仅进行假手术;正常组不做任何处理。分别于造模后第1,3,7,14天分批处死大鼠,检测梗阻侧肾小管间质纤维化损伤程度并检测肾脏组织中E-钙黏蛋白、整合素连接激酶蛋白的表达。 结果与结论：与正常组及对照组比较,模型组梗阻时间越长,肾小管间质损害程度越重,纤维化越明显。造模后3 d大鼠肾脏组织E-钙黏蛋白mRNA及其蛋白表达水平即出现下调,第14天最低,整合素连接激酶蛋白表达则显著增加,与同期正常组、对照组相比,差异有显著性意义(P < 0.05)。说明E-钙黏蛋白的表达减少促进了肾间质纤维化的发生、发展,而整合素连接激酶蛋白的表达增加在肾间质纤维化的进程中可能也发挥了重要作用。      

3-硝基酪氨酸在细菌内毒素诱导大鼠血管低反应性中的介导作用

目的：观察3-硝基酪氨酸（3-NT）对感染性休克大鼠血管低反应性的介导作用及抗氧化剂对此的治疗效果。 方法： 40只雄性SD大鼠随机分成空白对照组(n=10); LPS休克组（LPS 15 mg·kg-1 iv, n=10）; 尿酸(UA)治疗组（注射LPS 1 h后200 mg·kg-1 ip, n=10）; N-乙酰-5-甲氧基色胺（melatonin）治疗组（注射LPS 1 h后10 mg·kg-1 ip, n=10）。空白对照组及注射LPS 6 h后各组动物，静注去氧肾上腺素（PE, 0.5-2.5 μg·kg-1）,记录注药后MAP的增加百分比。所有in vivo实验结束后取大鼠胸主动脉环作张力实验,，建立PE的剂量-反应曲线并计算相应的Emax、EC50值。注射LPS 6 h后检测各组动物血浆丙二醛（MDA）、硝酸盐/亚硝酸盐（nitrate/nitrite）与3-NT的含量。 结果： 静脉注射PE后，休克组动物MAP的平均增长率与对照组相比显著降低至54.60%（P<0.01）；而UA组、melatonin组MAP对PE反应的增长率较之休克组分别增高了37.70%、40.03%(P<0.05)。休克组大鼠胸主动脉环对PE的反应［(Emax，35.30%±9.80%； EC50， (15.70±4.50)nmol/L］与对照组相比有显著差异［（Emax，100%； EC50， (4.71±2.04) nmol/L, P<0.05］，经UA、melatonin治疗后血管反应性有显著改善(P<0.05)。尿酸、N-乙酰-5-甲氧基色胺治疗组的血浆MDA、硝酸盐/亚硝酸盐和3-NT的浓度也明显低于休克组(P<0.05)。 结论： 3-NT是感染性休克血管低反应的重要介导因子，抗氧化剂通过清除氧自由基，减少脂质过氧化物的形成、抑制体内NO的过量合成及有效清除3-NT，从而改善α-肾上腺素能受体介导的血管低反应性，对临床感染性休克病人的治疗可能有积极作用。     

3-硝基酪氨酸与糖尿病心肌病大鼠心肌细胞凋亡的关系研究

目的：探讨2型糖尿病大鼠心肌组织及血中3-硝基酪氨酸（3-NT）与糖尿病心肌病（DCM）心肌细胞凋亡的关系。方法：选取8周龄雄性SD大鼠60只,将其随机分为4组,空白对照组、DCM组、糖尿病+缬沙坦处理组和DCM+缬沙坦处理组,每组15只。用TUNEL法检测DCM心肌细胞的凋亡指数（AI）;用免疫组化的方法检测心肌组织中3-NT的表达指数（EI）;用ELISA法检测血清中3-NT的浓度。结果：(1) 4组大鼠的心脏重量指数有显著差异（P<0.01）,DCM组和DCM+缬沙坦处理组心脏重量指数大于空白对照组和糖尿病+缬沙坦处理组。(2) 心肌组织免疫组化方法检测表明,心肌组织中3-NT的EI与心肌细胞的AI呈正相关（P<0.01）,而血中3-NT的含量与心肌细胞的AI无相关关系（P>0.05）。(3) 4组大鼠间的AI比较有显著差异（P<0.01）。两两比较各组AI,DCM组 > 糖尿病+缬沙坦预处理组、DCM+缬沙坦处理组 > 空白对照组。(4) 4组大鼠心肌组织3-NT表达指数比较有显著差异（P<0.01）;两两比较,DCM组显著大于其它3组。(5) 4组大鼠血中3-NT的浓度比较无显著差异（P>0.05）。结论：(1) DCM大鼠心肌组织中3-NT的表达显著增多并与心肌细胞凋亡密切相关,缬沙坦能够抑制DCM大鼠心肌细胞中3-NT的表达,并由此抑制DCM大鼠心肌细胞凋亡。(2) 循环血中的3-NT水平不能真实反映DCM大鼠心肌组织中3-NT表达水平及其对心肌细胞凋亡的影响。     

Persistent overexpression of SERCA2a affects bladder functions under physiological conditions, but not in bladder outlet obstruction-induced sub-acute pathological conditions

A functional impairment of the bladder and heart in a decompensated state caused by a pressure overload is accompanied by a decrease in the sarcoplasmic reticulum Ca²⁺-ATPase (SERCA2). The beneficial effects of SERCA2 overexpression in preserving cardiac functions have been previously reported. The aim of the present study was to investigate the effects of overexpressed SERCA2 on bladder functions under physiological and pathological conditions using partial bladder outlet obstruction (BOO) in SERCA2a transgenic Wistar rats (TG). Bladder cystometry and western blot analysis were performed using the wild-type Wistar rats (WT), TG, and BOO models (WTBOO and TGBOO). Persistent overexpression of SERCA2 induces reduced bladder compliance without hypertrophy in TG. BOO induces reduced bladder compliance and hypertrophy in WT and TG in the sub-acute phase, but persistent overexpression of SERCA2a in TG does not aggravate the bladder compliance and hypertrophy. In conclusion, SERCA2a overexpression affects bladder functions under physiological conditions, but not in BOO-induced sub-acute pathological conditions.     

Treatment for chronic ischaemia-induced bladder detrusor dysfunction using bone marrow mesenchymal stem cells: an experimental study

The mechanism of ischaemia-induced bladder dysfunction is not entirely clear, but is thought to be a result of the ischaemia-related M-receptor hypersensitivity to acetylcholine. In addition to nerve injury, ischaemia may cause bladder detrusor fibrosis and urethra de-epithelialization. Bladder dysfunctions caused by bladder outlet obstruction (BOO) and aging detrusor were considered to be associated with chronic ischaemia. To date, there has been no effective treatment for the histological and functional changes of the bladder caused by bladder ischaemia. The present study evaluated the feasibility and effectiveness of using bone marrow mesenchymal stem cells in the treatment of chronic ischaemia-induced bladder detrusor dysfunction in an experimental model. Bone marrow mesenchymal stem cells from Sprague-Dawley (SD) rats were injected into the common iliac artery of experimental animals, then bilateral iliac arteries were ligated and doxazosin mesylate was intragastrically administered. Eight weeks later, urodynamic examination and intravesical pressure measurements were performed on experimental animals. Histological changes of the taken bladder from sacrificed SD rats were evaluated by immunohistochemistry and trichrome staining and the images captured were analyzed by a software program. The average intravesical pressure and detrusor contraction power of the ischaemia group was 16.21±5.26 and 17.26±5.72; those of the experimental group were 24.02±10.06 and 25.84±11.99; the average intravesical pressure and detrusor contraction power of the control group was 28.56±4.48 and 29.57±5.01. The average intravesical pressure and detrusor contraction power of the ischaemia group were significantly lower than those of the experimental and control group, while no significant difference was shown between the experimental and control groups. 5-Bromo-2'-deoxyuridine (BrdU) staining for the experimental group was positive. The percentage of the smooth muscle content in the bladder wall was (25.21±6.28)%, (49.38±6.32)% and (48.00±17.39)% for ischaemia, experimental and control group, respectively. The percentage of smooth muscle in the bladder wall of the ischaemia group was significantly lower than that of the experimental and control group, while no significant difference was observed between the experimental and control groups. The number of nerve fibers per high power field of the experimental group was significantly higher than that of the ischaemia group, but lower than the control group. In conclusion, the percentage of smooth muscle content and the number of nerve cells per high power field decreases in ischaemia bladder, with detrusor contractility decreased. Injection of stem cell suspension into the common iliac artery in rats with ischaemic bladder, followed by intragastric administration of doxazosin mesylate, makes transplanted stem cells regenerate in the bladder tissue, increases the percentage of smooth muscle content and nerve cells per high power field in the bladder wall, and improve bladder detrusor contraction function.     

Morphologic and functional heterogeneous changes of the urinary bladder different parts at rats with infravesical obstruction of the urinary tracts

Infravesical obstruction of the lower urinary tracts of 30 rats was carried out by the measured constriction of the urethral prevesical parts. Morphologic and functional changes of the urinary bladder different parts were studied in 1 week and in 3 months. Compensatory hypertrophy of the detrusor was accompanied increasing of hypertrophied, atrophic and native forms of leiomyocytes, as so their transformation into myofibroblasts with connective tissue formation between the muscle fibers mainly in the neck of urinary bladder Contractility of the detrusor decreased with their tonus increasing mainly in the neck of urinary bladder too. Weakening effect of adrenalin in 3 month after obstruction significantly decreased, while in the body and neck of urinary bladder it virtually disappeared. Blockade of alpha-adrenoreceptors after noradrenalin stimulation resulted in enchancement of the hypertrophic detrusor contraction when tonus of the urinary neck decreased. On the contrary, in the intact urinary bladder the similarly influence resulted in weakening of contraction.     

PAX2-siRNA在梗阻性肾病大鼠体内的作用研究

目的 通过RNA干扰和基因转染技术,研究沉默PAX2基因对UUO大鼠肾间质纤维化的影响.方法 将PAX2-siRNA转染至UUO大鼠肾脏被膜下,将64只幼年雄性大鼠随机分为:阴性对照组(NC)32只;沉默组(RNAi) 32只,于转染后3、5、7、14天分为4组,每组8只,留取肾组织标本,应用Real-Time PCR及Western blot检测肾皮质PAX2 mRNA及其蛋白的沉默情况,HE染色和Masson染色方法在光镜下观察肾小管损伤情况和肾间质纤维化程度.结果 ①沉默组与对照组比较PAX2 mRNA和PAX2蛋白表达量降低,有统计学意义(P＜0.05),②HE和Masson染色观察到对照组随梗阻时间延长,肾小管损伤逐渐明显,肾间质中可见胶原蛋白逐渐增加.沉默组与对照组比较在7d以前无明显变化(P＞0.05);在梗阻14d沉默组与对照组比较肾小管损伤减轻、肾间质病变减低、胶原纤维沉积减少(P＜0.05).结论 在UUO大鼠模型中,梗阻早期沉默PAX2基因对肾间质纤维化进程无明显影响,梗阻晚期可减轻肾小管损伤及肾间质纤维化病变,对肾间质纤维化有明显治疗作用.     

输尿管梗阻及再通大鼠肾组织中单核-巨噬细胞相关因子动态表达

目的 探讨输尿管梗阻及再通大鼠肾间质纤维化发生和恢复过程中单核-巨噬细胞相关因子的动态表达。方法 将48只SD大鼠随机分成梗阻和再通两个实验部分,梗阻部分分为假手术组（sham,n=6）、单侧输尿管梗阻（UUO）3d（n=6）、UUO 7d（n=6）和UUO 14d（n=6）;再通部分分为双侧输尿管梗阻（RBUO）0d（n=6）、RBUO后再通3d（n=6）、RBUO后再通 7d（n=6）和RBUO 后再通14d（n=6）。术后3、7和14 d后处死取其肾脏组织。采用HE和Masson染色观察肾组织病理改变和间质纤维化程度;免疫组织化学染色检测肾组织内单核细胞趋化蛋白-1（MCP-1）、巨噬细胞克隆刺激因子（M-CSF）和活化巨噬细胞标志物CD68的表达水平;Real-time PCR检测MCP-1和M-CSF mRNA表达水平;ELISA测定TGF-β1含量。 结果 与Sham大鼠相比,UUO大鼠随着梗阻时间延长,纤维化程度加剧。同时TGF-β1水平明显升高。输尿管再通后,纤维化程度随时间延长明显减轻,且TGF-β1水平明显下调。UUO大鼠肾组织中,MCP-1和M-CSF mRNA和表达蛋白随梗阻时间延长而增加;梗阻再通后,MCP-1和M-CSF mRNA和蛋白表达随再通时间延长持续下降。MCP-1和M-CSF在UUO或再通大鼠肾组织中的表达与CD68呈现一致性变化趋势。 结论 输尿管梗阻后,M-CSF和MCP-1的动态表达反映单核-巨噬细胞的活化和聚集状态,这可能是间质纤维化发生十分重要的炎症基础。而输尿管再通可抑制活化和趋化的单核-巨噬细胞,控制炎症反应,缓解肾间质纤维化。     

三七总皂苷对异丙肾上腺素所致大鼠心肌肥厚和纤维化的影响

目的：研究三七总皂苷（PNS）对异丙肾上腺素所致大鼠心肌肥厚和纤维化的保护作用。方法： 用异丙肾上腺素（ISO）5 mg·kg^-1·d^-1,sc,连续7 d，建立大鼠心肌肥厚和纤维化模型。造模第2 d开始给大鼠腹腔注射PNS 25和50 mg· kg^-1·d^-1,连续14 d，测定全心重量指数（HW/BW）、左心室重量指数（LVW/BW即LVI）；采用试剂盒用分光光度法检测左心室心肌组织中羟脯氨酸（Hyp）、丙二醛（MDA）、一氧化氮（NO）含量和超氧化物歧化酶（SOD）、谷光苷肽过氧化酶（GSH-Px）、一氧化氮合酶（NOS）活性；用放免分析法检测左心室心肌组织中血管紧张素Ⅱ（AngⅡ）含量。结果： ISO模型组大鼠的HW/BW、LVI、左心室HyP、AngⅡ、MDA含量和诱生型NOS(iNOS)活性显著高于生理盐水对照组，SOD、GSH-Px及结构型NOS(cNOS)活性和NO含量明显比生理盐水对照组低；PNS治疗组左心室心肌组织中NO含量、cNOS 、SOD和GSH-Px活性明显高于ISO模型组；MDA和AngⅡ含量及iNOS活性和心脏重量指数比ISO模型组低。结论： PNS有抗心肌肥厚和纤维化作用，该作用与清除氧自由基及升高NO含量有关。     

Urinary outflow obstruction increases apoptosis and deregulates Bcl-2 and Bax expression in the fetal ovine bladder

During organogenesis, net growth of tissues is determined by a balance between proliferation, hypertrophy, and apoptotic death. Human fetal bladder outflow obstruction is a major cause of end-stage renal failure in children and is associated with complex pathology in the kidney and lower urinary tract. Experimental manipulation of the fetal sheep urinary tract has proved informative in understanding the pathobiology of congenital obstructive uropathy. In this study we used an ovine model of fetal bladder outflow obstruction to examine effects on apoptotic cell death in the developing urinary bladder. While 30 days of obstruction in utero between 75 and 105 days gestation resulted in overall growth of the fetal bladder as assessed by weight, protein, and DNA measurements, we found that apoptosis, as assessed by in situ end-labeling, was up-regulated in fetal bladder detrusor muscle and lamina propria cells and that this was accompanied by a down-regulation of the anti-death protein Bcl-2 and an up-regulation of the pro-death protein Bax. Moreover, activated caspase-3, an effector of apoptotic death, was increased in obstructed bladders. This is the first study to define altered death in an experimental fetal model of bladder dysmorphogenesis. We speculate that enhanced apoptosis in detrusor smooth muscle cells is part of a remodeling response during compensatory hyperplasia and hypertrophy. Conversely, in the lamina propria, an imbalance between death and proliferation leads to a relative depletion of cells.     

黄芩素对野百合碱诱导的肺动脉高压大鼠血管壁增厚的抑制作用

目的:观察黄芩素(baicalein)对野百合碱(monocrotaline,MCT)诱导的肺动脉高压(pulmonary artery hypertension,PAH)大鼠的治疗作用,并初步探讨其机制。方法 :28只雄性SD大鼠随机分为对照组、MCT模型组、黄芩素低剂量组和黄芩素高剂量组。除对照组外,其余各组大鼠皮下注射MCT建立大鼠PAH模型,黄芩素低、高剂量组于MCT注射2周后分别灌胃黄芩素50和100 mg·kg~(-1)·d~(-1),持续14 d,对照组灌胃等量生理盐水。造模4周后,测定大鼠右心室收缩压(right ventricular systolic pressure,RVSP)、右心室肥厚指数(right ventricular hypertrophy index,RVHI)和右心室质量指数(right ventricular mass index,RVMI);Masson染色检测肺组织纤维化程度;HE染色观察肺血管病理形态学变化;Western blot测定各组肺组织α-平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)蛋白水平及肺小动脉p38、ERK和JNK的磷酸化水平。结果:与对照组比较,MCT模型组大鼠的RVSP、RVHI和RVMI均明显升高(P0.01),肺组织纤维化明显,肺组织中α-SMA表达上调(P0.01),肺动脉壁增厚,肺小动脉p38,ERK和JNK磷酸化水平明显升高(P0.01);与MCT模型组相比,黄芩素高、低剂量组的RVSP、RVHI和RVMI明显降低(P0.01),肺组织纤维化和血管壁增厚明显改善,p38、ERK和JNK的磷酸化水平减少(P0.01)。结论:黄芩素可减轻MCT诱导的肺动脉高压,其作用通过抑制肺动脉壁增厚来实现,其分子机制可能与其抑制肺动脉的MAPK信号通路有关。     

Heterogeneity of Morphological and Functional Changes in Various Compartments of Rat Urinary Bladder in Infravesical Obstruction of the Urinary Tract

Infravesical obstruction of the lower urinary tract was simulated in rats by dosed constriction of the prevesical portion of the urethra. The functional and morphological changes in various urinary bladder compartments were evaluated after 1 week and 3 months. The development of compensatory hypertrophy of the detrusor was associated with an increase in the number of hypertrophic, atrophic, and young leiomyocyte forms and their transformation into myofibroblasts, with the formation of connective tissue laminae between myofibril bundles mainly in the zone of urinary urinary bladder neck. Specific contractility of the detrusor strips decreased with increasing their tone, which was most pronounced in the neck zone. The relaxing effect of norepinephrine was significantly lower after 3 months of obstruction and virtually disappeared in the zone of the urinary bladder body and neck. Blockade of α-adrenoceptors after adrenostimulation with norepinephrine stimulated contractions of the hypertrophic detrusor against the background of reduced tone of the urinary bladder neck, in contrast to intact urinary bladder where this treatment reduced contractions. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny , Vol. 147, No. 1, pp. 108-112, January, 2009     

Myocardial Morphological Characteristics and Proarrhythmic Substrate in the Rat Model of Heart Failure Due to Chronic Volume Overload

Chronic volume overload leads to cardiac hypertrophy and later to heart failure (HF), which are both associated with increased risk of cardiac arrhythmias. The goal of this study was to describe changes in myocardial morphology and to characterize arrhythmogenic substrate in rat model of developing HF due to volume overload. An arteriovenous fistula (AVF) was created in male Wistar rats between the inferior vena cava and abdominal aorta using needle technique. Myocardial morphology, tissue fibrosis, and connexin43 distribution, localization and phosphorylation were examined using confocal microscopy and Western blotting in the stage of compensated hypertrophy (11 weeks), and decompensated HF (21 weeks). Heart to body weight (BW) ratio was 89% and 133% higher in AVF rats at 11 and 21 weeks, respectively. At 21 weeks but not 11 weeks, AVF rats had pulmonary congestion (increased lung to BW ratio) indicating presence of decompensated HF. The myocytes in left ventricular midmyocardium were significantly thicker (+8% and +45%) and longer (+88% and +97%). Despite extensive hypertrophy, there was no excessive fibrosis in the AVF ventricles. Distribution and localization of connexin43 were similar between groups, but its phosphorylation was significantly lower in AVF hearts at 21st week, but not 11th week, suggesting that HF, rather than hypertrophy contributes to the connexin43 hypophosphorylation. In conclusion, volume overload leads to extensive eccentric hypertrophy, but not to myocardial fibrosis. Increased vulnerability to arrhythmia in this HF model is possibly related to gap junction remodeling with hypophosphorylation of connexin43. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.     

PAI-1和TIMP-1基因在肾小管间质纤维化中的表达及HGF的干预作用

目的:研究纤溶酶原激活物抑制剂1(PAI-1)和组织基质金属蛋白酶抑制剂1(TIMP-1)基因表达与梗阻性肾病小管间质纤维化(TIF)进展的关系及肝细胞生长因子(HGF)的干预作用。方法: 60只Wistar大鼠随机分为4组:正常大鼠组、假手术组、单侧输尿管梗阻组和HGF治疗组,分别于模型3 d、7 d、14 d、21 d处死大鼠。采用逆转录多聚酶链反应(RT-PCR)检测PAI-1和TIMP-1 mRNA表达水平;底物酶谱法检测肾脏MMP2、9活性的变化,测定肾组织羟脯氨酸含量判断纤维化程度。结果:梗阻肾组织PAI-1和TIMP-1 mRNA表达显著高于对照组,并伴有明显的梗阻肾MMP2,MMP9活性低于和羟脯氨酸含量高于对照组,而21 d HGF治疗组PAI-1和TIMP-1 mRNA表达明显下调,MMP2,MMP9活性高于和肾组织羟脯氨酸含量少于对照组。结论: PAI-1、TIMP-1 mRNA表达增高是小管间质ECM降解减少的主要原因之一,也是造成TIF加重的重要因素,而HGF可拮抗这一进程,减轻小管间质纤维化。     

单侧输尿管梗阻模型大鼠肾间质纤维化过程中血小板衍生生长因子D的表达

背景：血小板衍生生长因子在肾间质中通过诱导肾小管间质细胞增生、表型转化、炎性细胞浸润等导致肾小管间质纤维化。 目的：观察血小板衍生生长因子D在单侧输尿管梗阻模型大鼠肾脏组织中的表达水平及随时间的演变情况。 方法：将成年健康雄性SD大鼠60只随机分为模型组及假手术组,将模型组大鼠左侧输尿管结扎剪断建立单侧输尿管梗阻模型,假手术组大鼠不结扎剪断仅游离左侧输尿管。术后3,7,14,21,28 d,通过免疫组化检测血小板衍生生长因子D在肾脏组织中的表达分布情况,实时荧光定量RT-PCR方法检测血小板衍生生长因子D mRNA的表达水平及变化。 结果与结论：假手术组血小板衍生生长因子D仅少量表达于肾小球系膜细胞及血管平滑肌细胞,而在模型组,血小板衍生生长因子D同时表达于肾间质纤维化区域,随纤维化程度加重,表达增多。同时模型组血小板衍生生长因子D mRNA表达量较假手术组显著增多(P < 0.05),且表达随时间延长逐渐增多。提示血小板衍生生长因子D在单侧输尿管梗阻模型肾间质纤维化过程中发挥着促纤维化的重要意义。     

Fibrotic response to angiotensin II is blunted in the kidney, but not in the heart, in insulin-sensitive long-lived transgenic dwarf rats

Insulin resistance is a characteristic feature of cardiovascular and renal diseases, and angiotensin II (Ang II) has been suggested to induce insulin resistance. The aims of this study were to elucidate the effect of chronic Ang II infusion on vascular reactivity and organ damage in insulin-sensitive rats. We confirmed the following three points. First, there was no significant difference in pressor response to chronic Ang II infusion (600 ng/kg/min) between insulin-sensitive transgenic rats (Tg) and control rats (C). Second, there was no significant difference in cardiac hypertrophy and fibrosis by chronic Ang II infusion between the two groups. However, third, fibrotic response to chronic Ang II infusion evaluated by histopathological scoring in the kidney was significantly decreased in insulin-sensitive transgenic rats (renal fibrosis and nephropathy score: C+Ang II vs Tg+Ang II; 2.5 vs 1.3; p<0.05). Furthermore, the expression of TGF-beta, a fibrosis indicator, was also significantly suppressed in the kidneys of the transgenic rats (TGF-beta1/GAPDH ratio: C+Ang II vs Tg+Ang II; 1.15 vs 0.81; p<0.05). This result indicates that the growth hormone/insulin-like growth factor-1 axis is critically involved in the development of renal injury and fibrosis, rather than hypertension, cardiac hypertrophy, and cardiac fibrosis induced by chronic Ang II administration.