非胰岛素依赖型糖尿病大鼠膀胱兴奋性自律性以及舒缩功能的改变

目的研究非胰岛素依赖型糖尿病(NIDDM)大鼠的逼尿肌功能变化情况，为进一步阐明糖尿病膀胱病变的发病机理提供实验依据。方法制造NIDDM大鼠模型，以正常大鼠为对照，分别进行残余尿测定，在体膀胱灌注测压观察膀胱最大容量、膀胱顺应性改变和最大逼尿肌收缩强度(即瓦特因子)以及采用离体逼尿肌条研究膀胱兴奋性、自律性及收缩力变化。结果糖尿病组大鼠膀胱逼尿肌兴奋性明显低于对照组，自律性呈现先高后低趋势，最大收缩力和平均收缩力较对照组降低；膀胱顺应性升高，残余尿增多、膀胱容量增大以及膀胱湿重增加。结论膀胱逼尿肌兴奋性降低是NVUDD的改变最早且最明显的指标。在糖尿病早期就存在逼尿肌自主节律性的变化。最初频率增加的原因可能是于逼尿肌兴奋性降低的代偿所致，其后表现为频率降低则是失代偿的结果。糖尿病对于膀胱收缩、舒张功能均有损害作用，从而导致膀胱顺应性改变。     

糖尿病对膀胱逼尿肌兴奋性、收缩性及顺应性影响的实验研究

目的:探讨糖尿病(DM)对膀胱逼尿肌兴奋性、收缩性、顺应性的影响及糖尿病神经源性膀胱尿道功能障碍(NVUDD)的发病机制.方法:建立SD大鼠DM动物模型,于10周后行充盈性膀胱测压及离体逼尿肌条机械牵拉、电及胆碱类药物刺激试验.结果:DM动物模型10周后不稳定膀胱(DI)的发生率为64.7%,逼尿肌顺应性升高;DI组、DM后稳定组与正常对照组相比,牵拉逼尿肌致其出现收缩时的张力明显降低,电刺激产生的收缩力明显减弱;DI组逼尿肌胆碱类药物产生的收缩力明显减弱.结论:DM后NVUDD的发生率较高,其逼尿肌的收缩功能受损较重,DNBUD的发生与逼尿肌自身的神经源及肌源性改变密切相关.     

糖尿病膀胱尿动力学及逼尿肌功能改变的相关性研究

目的探讨糖尿病膀胱尿动力学变化与逼尿肌功能改变之间的相关性。方法回顾性分析70例糖尿病患者尿动力学检查结果,将患者分为早期组(病史<8年〉和进展期组(病史>12年),分别测定初尿意的膀胱容量、最大膀胱容量、最大自由尿流率、PQmax、剩余尿量。并结合2型糖尿病(T2DM)大鼠与正常大鼠的离体逼尿肌肌条实验,分析实验鼠发病6周和18周的逼尿肌兴奋性、最大收缩力和平均收缩力变化。结果临床资料显示29例(41%)表现为低顺应性膀胱,28例(40%)膀胱感觉减退,30例(43%)排尿期逼尿肌压力减退,22例(31%)剩余尿量超过150ml,10例(14%)逼尿肌不稳定,6例(9%)不能自行排尿。患者膀胱灌注过程中产生初尿意的灌注容量(203.25±107.53)ml(125~630ml),最大膀胱容量(428.09±227.89)ml(220~1350ml)。最大自由尿流率(10.70±3.27)ml/min,剩余尿量(100.57±108.08)ml,早期组患者产生初尿意的膀胱容量增加为(151.67±24.07)ml,进展期患者初尿意的膀胱容量增加为(268.16±13.90)ml,最大膀胱容量(592.97±252.51)ml,最大自由尿流率(8.61±2.04)ml/min,PQmax(33.16±19.81)cmH2O(1cmH2O=0.098kPa),剩余尿增加至(169.03±137.25)ml。动物实验发现T2DM大鼠逼尿肌的张力阈值为(0.72±0.33)g,显著高于对照组(0.32±0.18)g,F=59.63,P<0.0001;最大逼尿肌收缩力T2DM组(0.08±0.04)g,较对照组(0.11±0.05)g降低(F=7.47,P<0.01);平均收缩力T2DM组(0.06±0.02)g,较对照组(0.07±0.03)g明显降低(F=5.71,P<0.05)。随着实验动物发病时间延长,T2DM大鼠逼尿肌张力阈值呈现增高趋势,而逼尿肌最大及平均收缩力均降低。结论根据临床及动物实验结果推测,早期糖尿病患者膀胱感觉减退可能是逼尿肌兴奋性降低的缘故。进展期膀胱感觉进一步减退、最大膀胱容量显著增大、最大自由尿流率降低、排尿期最大尿流时的逼尿肌压力降低、剩余尿量显著增多等一系列尿动力学改变,可能是在逼尿肌兴奋性改变的基础上出现逼尿肌收缩力降低的结果。     

肾上腺素β3受体与梗阻后逼尿肌不稳定关系的实验研究

目的　探讨肾上腺素β3 受体 (β3 AR)在膀胱出口梗阻 (BOO)型逼尿肌不稳定 (DI)中的作用。　方法　Wister大鼠 15只 ,建立BOO后DI模型 ,6周后行充盈性膀胱测压 ,根据是否有DI将下尿路梗阻大鼠分为DI组和逼尿肌稳定 (DS)组 ,正常大鼠 8只作为对照组。用离体逼尿肌条拉力实验观察BRL37344A(β3 AR激动剂 )对逼尿肌自律性和舒张功能的影响 ,RT PCR检测膀胱 β3 ARmRNA含量。　结果　BOO后DI发生率为 6 7% (10 / 15 )。BRL37344A能明显抑制正常及不稳定膀胱逼尿肌自发性收缩频率及收缩强度 ,作用呈浓度依赖性 ,对DI组的作用强度明显低于正常对照组及梗阻后DS组 (P <0 .0 5 ) ;梗阻后DI组、对照组及梗阻组 β3 ARmRNA相对含量分别为 10 .2 7± 1.17、19.84± 2 .6 2和 18.38± 3.4 5 ,DI组明显降低 (P <0 .0 5 )。　结论　β3 AR激动剂能降低正常及梗阻后逼尿肌条自律性及收缩力 ,β3 AR密度变化可能参与大鼠BOO后逼尿肌不稳定的发生。     

逼尿肌活动过度伴收缩功能受损对膀胱排空的影响

目的探讨逼尿肌活动过度伴收缩功能受损(DHIC)对膀胱排空功能的影响。方法通过压力流率测定分别对99例DHIC和176例单纯逼尿肌收缩力减弱的患者(对照组)进行评估,对相应资料进行统计学分析。结果DHIC组患者的剩余尿量、最大尿流率(Qmax)、最大尿流率时逼尿肌压(PdetQmax)、膀胱顺应性、膀胱容量(V)分别为(106.40±149.55)ml、(5.91±3.24)ml/s、(44.52±17.78)cmH2O、(26.34±48.16)ml/cmH2O和(228.28±93.36)ml,对照组分别为(228.88±241.71)ml、(4.13±3.10)ml/s、(34.42±20.82)cmH2O、(66.96±97.53)ml/cmH2O和(328.30±123.19)ml,2组比较差异均有统计学意义(P<0.05)。有膀胱出口梗阻的DHIC(44例)与有梗阻的单纯逼尿肌收缩力减弱患者(52例)相比,剩余尿量、膀胱顺应性和V的差异有统计学意义(P<0.05)。口服黄酮哌酯或舍尼亭出现尿潴留者16例。有上尿路扩张者11例,其中DHIC者8例。结论DHIC的膀胱排空能力高于单纯逼尿肌收缩力减弱者。应谨慎应用抑制逼尿肌收缩的药物。DHIC患者膀胱顺应性较低,应警惕可能发生上尿路损害。     

糖尿病大鼠逼尿肌细胞内游离钙离子浓度的变化

目的观察2型糖尿病(T2DM)大鼠的逼尿肌细胞内游离钙离子浓度变化,为阐明糖尿病膀胱病变的发病机制提供依据。方法制备T2DM大鼠模型,在成模后4周和20周,以正常大鼠为对照,分离单个逼尿肌细胞并应用Fura-2／AM荧光探针负载,进行细胞内钙离子浓度的测定。结果发病初期,T2DM大鼠逼尿肌细胞内静息钙离子荧光比值(289．24±33．80)与正常对照组(276．85±57．90)比较,差异无统计学意义。在发病20周时,T2DM组大鼠逼尿肌细胞内钙离子荧光比值(545．94±79．28)比正常对照组(275．66±108．94)明显增高。结论细胞内钙超载参与了逼尿肌功能的损害的病理过程,但是发生相对较晚,可能在糖尿病膀胱发病的进展期起重要作用。     

糖尿病患者膀胱功能改变的临床研究

目的 :探讨糖尿病患者膀胱功能变化及其机制。方法 :将 70例糖尿病患者按照病程分为早期组和进展期组 ,分别对其初尿意的膀胱容量、最大膀胱容量、最大自由尿流率、最大尿流时的逼尿肌压力 (PQmax)、剩余尿量进行分析。结果 :早期组糖尿病患者产生初尿意的膀胱容量增大至 (15 1.6 7± 2 4 .0 7)ml,进展期糖尿病患者初尿意的膀胱容量进一步增大至 (2 6 8.16± 13.90 )ml,最大膀胱容量增大至 (5 92 .97± 2 5 2 .5 1)ml,最大自由尿流率降低至 (8.6 1± 2 .0 4 )ml/min ,PQmax降低 (3.2 5± 1.94 )kPa ,剩余尿量增加至 (16 9.0 3± 137.2 5 )ml。结论 :早期糖尿病患者膀胱感觉减退可能是逼尿肌兴奋性降低的缘故 ;进展期糖尿病患者的一系列尿动力学改变 ,可能是在逼尿肌兴奋性改变的基础上出现逼尿肌收缩力降低的结果。     

脑血管意外尿失禁的机制探讨

目的探讨脑血管意外引起尿失禁的可能机制。方法对42例诊断为脑血管意外伴有尿失禁的患者进行尿动力学检查(包括静止期尿道压测定、充盈期及排尿期膀胱尿道功能测定)并按Burney分类进行分析,同时研究病变部位、脑血管意外性质和病变半球侧与尿动力学的关系。结果42例脑血管意外患者中,表现为逼尿肌反射亢进者31例(73.8%):其中外括约肌无抑制性松弛19例(45.2%),逼尿肌-外括约肌不协调3例(7.1%),逼尿肌-外括约肌协调9例(21.4%);逼尿肌反射减低,外括约肌协调者11例(26.2%);无逼尿肌功能正常者。发生膀胱顺应性减低5例(11.9%),发生尿感缺失者11例(26.2%)。初感尿容量(140.00±46.97)ml;膀胱最大容量(293.20±60.71)ml;最大尿道闭合压(65.14±19.83)cmH2O。逼尿肌最大收缩力(Pdetmax)为(60.98±31.11)cmH2O;最大尿流率时逼尿肌压力(Pdet-Qmax)为(35.98±17.46)cmH2O;逼尿肌收缩时间(Tcon)为(86.07±36.09)sec;最大流量(Qmax)为(9.02±5.62)ml/s。中风后尿失禁患者其发病部位多见于基底节、皮层多灶以及额顶叶,脑出血与脑梗塞患者的尿动力学表现无明显差异,左右半球病变对尿动力学也无明显差异。结论脑血管意外后尿失禁的尿动力学异常主要为逼尿肌反射亢进,部分出现逼尿肌反射减弱,但感觉正常,感觉缺失者较少见;外括约肌功能以无抑制性松弛为主,其次为逼尿肌-外括约肌协调,少数出现不协调;较少出现膀胱顺应性降低。     

非胰岛素依赖型糖尿病大鼠逼尿肌兴奋性及自律性改变

目的　研究非胰岛素依赖型糖尿病(NIDDM)大鼠的逼尿肌兴奋性及自律性的变化。方法　制作NIDDM大鼠模型,以正 常大鼠为对照,采用离体逼尿肌条研究膀胱兴奋性和自律性变化。结果　NIDDM组引起逼尿肌肌条自发收缩的张力阈值 [(0.716±0.325)g]明显高于对照组[(0.323±0.177)g](F=59.63,P<0.0001),不同时间段NIDDM组引起逼尿肌收缩的张 力阈值也高于对照组。NIDDM组逼尿肌自发收缩的频率在第6～18周的变化较对照组增高,在第22、26周较对照组减低。 结论　膀胱逼尿肌兴奋性降低是糖尿病膀胱功能最早且最明显的改变。逼尿肌自主节律性改变也是糖尿病膀胱的早期变化之一。     

膀胱出口部分梗阻后膀胱功能和组织学变化的相关性研究

目的了解膀胱出口部分梗阻后膀胱功能和组织学形态变化的相关性。方法16只雄性Wistar大鼠分2组,每组8只。第1组为对照组,第2组手术建立膀胱出口部分梗阻动物模型。6周后对2组大鼠进行尿动力学膀胱测压,并采用双免疫组织化学方法分析膀胱平滑肌和胶原的比例,电镜观察超微结构。结果6周后,2组动物逼尿肌收缩力分别为(34.5±7.1)cmH2O(1cmH2O=0.098kPa)和(15.0±7.2)cmH2O,2组比较差异有统计学意义,P<0.001。第2组最大膀胱灌注量为(3.7±0.9)ml,明显高于对照组的(1.2±0.2)ml,P<0.001;第2组膀胱顺应性为(0.170±0.060)ml/cmH2O,也明显高于对照组的(0.065±0.017)ml/cmH2O,P<0.001。梗阻后膀胱重量明显增加,第2组膀胱重量为(0.478±0.127)g,高于对照组的(0.131±0.020)g,P<0.001。2组膀胱平滑肌与胶原的比例分别为4.7±0.7和5.1±1.1,差异无统计学意义(P>0.05)。电镜观察发现梗阻后平滑肌细胞器有退行性改变。结论大鼠膀胱出口部分梗阻6周后膀胱功能受到损害,膀胱重量明显增加,为膀胱平滑肌和胶原共同增生所致。     

糖尿病膀胱的尿动力学及病理学改变(附动物实验与临床观察)

目的:观察糖尿病膀胱(DCP)的尿动力学及病理学改变,探讨发病机制及病理演绎过程.方法:建立DCP wistar大鼠模型(30只),正常wistar大鼠作对照(30只),进行膀胱储尿期压、最大容量、最大膀胱压等测定,进行膀胱湿重、膀胱壁厚度及光镜、电镜的病理学观察.早期DCP患者(32例),晚期DCP(28例)及非DM人群(22例)进行尿流率、压力-流率尿道分布压及括约肌肌电图等测定,作相关统计学处理.结果:①60天后,DCP鼠组与对照组:膀胱储尿期压(0.45±0.08)kPa,(0.60±0.03)kPa(P＜0.05);最大膀胱容量(3.49±0.40)ml,(1.82±0.12)ml(P＜0.01);最大膀胱压(3.09±0.10)kPa,(4.91±0.30)kPa(P＜0.01);膀胱顺应性(1.39±0.11)ml·kPa-1,(0.68±0.07)ml·kPa-1(P ＜0.01);湿重增加(P ＜0.01);逼尿肌细胞连接纤维化,成纤维细胞变性及胶原纤维排列紊乱.②相对于对照组,早期DCP患者最大尿流率偏低,为(15.97±5.71)ml·s(P ＜0.05),逼尿肌活动亢进(占59%),逼尿肌/括约肌协同失调(占37.5%);而晚期DCP患者最大尿流率明显下降,为(8.75±4.20)ml·s-1(P ＜0.01),膀胱容量增加,为(472.5±32.9)ml(P ＜0.01),剩余尿量增多,为(62.59±19.87)ml(P ＜0.01),逼尿肌收缩功能减弱.结论:DCP早期就有膀胱的动力学及病理学改变,以逼尿肌活动功能亢进,逼尿肌/括约肌协同失调较常见,晚期以逼尿肌收缩功能减弱为主,建议对DCP患者早期就应给予干预,控制病情的进一步恶化.     

早期糖尿病膀胱尿动力学及cajal样细胞的变化和意义

目的：观察早期糖尿病在膀胱尿动力学和cajal样细胞上的病理学改变,探讨其发生机制及病理演绎过程。方法：建立早期糖尿病豚鼠模型40只（病变组）,以正常豚鼠20只作对照（对照组）,饲养10周后行膀胱最大收缩压、漏尿点压等尿动力学指标测定。然后将两组豚鼠膀胱制作成冷冻切片行免疫荧光染色及激光共聚焦显微镜观察。结果：10周后,与对照组比较,病变组膀胱最大容量（P〈0．05）、漏尿点压（P〈0．01）、顺应性（P〈0．05）、剩余尿量（P〈0．01）增加,而膀胱静息压（P〈0．01）、最大逼尿肌压（P〈0．05）下降,激光共聚焦显微镜下见糖尿病组膀胱逼尿肌中cajal样细胞数量减少（P〈0．01）,cajal样细胞二聚体消失（P〈0．01）。结论：糖尿病膀胱病变豚鼠早期有尿动力学异常,cajal样细胞数量减少并伴有该细胞二聚体结构消失,提示早期糖尿病膀胱病变是高糖环境下发生了具有起博功能的cajal样间质细胞异常,从而使逼尿肌功能障碍及尿动力学发生改变;而真正起逼尿功能的平滑肌细胞失去该细胞起博而处于一种待激发的”休眠状态”。因此,l临床上应针对这种情况进行干预,以控制病情的进一步恶化。     

糖尿病大鼠膀胱重构中M3受体改变的实验研究

目的:研究病程24周的2型糖尿病大鼠膀胱重构时,逼尿肌收缩功能的改变和M3受体含量及其基因转录水平的改变情况,并探讨二者之间的相关性。方法:2d龄雌性Wistar大鼠随机分成实验组和正常对照组,应用链脲佐菌素腹腔注射并结合高糖高脂饮食进行2型糖尿病大鼠动物模型制备。于糖尿病病程24周时进行下列实验:应用离体膀胱灌注方法观察逼尿肌收缩功能的变化;应用RT-PCR和Western blotting方法观察逼尿肌M3受体mRNA和蛋白表达的变化。结果:2型糖尿病组大鼠逼尿肌收缩功能低于正常对照组,为(16.52±2.97)cmH2O/100mgVS(25.66±3.56)cmH2O/100mg;2型糖尿病组大鼠逼尿肌M3受体mRNA和蛋白的表达均高于正常对照组,分别为(65.27±4.61)%VS(37.53±4.02)%和(45.19±2.37)%VS(23.67±2.85)%。结论:本研究证实了2型糖尿病大鼠在病程24周时膀胱逼尿肌的收缩力降低,但M3受体的生物合成却上调,这种不平行现象可能是病变进展的表现,为深入研究糖尿病膀胱病的发病机制提供了有价值     

Effect of substance P on detrusor muscle in rats with diabetic cystopathy.

Diabetic cystopathy (DCP) is a well known complication in diabetes mellitus (DM). In the present experimental study, DM was induced in rats by streptozotocin and DCP was confirmed on cystometry. In vitro studies on detrusor strips from diabetic rats showed an increased contractile response to substance P (SP) compared with controls, indicating denervation supersensitivity. A decreased response to capsaicin in diabetic detrusor strips indicated a decreased neuronal content of SP or a diminished number of SP-containing sensory nerves. This suggests that DM induces alterations in nerves containing SP which may be at least partly responsible for sensory loss and the development of DCP.     

Efficacy and safety of propiverine in SCI-patients suffering from detrusor hyperreflexia--a double-blind, placebo-controlled clinical trial

AIMS OF THE STUDY: The aim of this double-blind, randomised, prospective, multicentre trial was to evaluate the efficacy of propiverine in patients suffering from detrusor hyperreflexia caused by spinal cord injury in comparison to placebo. STUDY DESIGN: The treatment period of 14 days comprised visits at baseline (V1) and after 14 days treatment (V2). Fifteen mg propiverine t.i.d. or placebo t.i.d. were administered as medication. The following efficacy parameters were adopted: the urodynamic parameters maximal cystometric bladder capacity, bladder volume on onset of the first as well as duration and amplitude of the maximum detrusor contraction, bladder compliance and residual urine, and subjective assessment of efficacy by physicians. For the evaluation of the safety of propiverine the incidence rate of adverse events by directly questioning as well as laboratory parameters were investigated. For biometrical evaluation t-test for independent groups was applied. RESULTS: One hundred and thirteen patients were investigated. The maximal cystometric bladder capacity increased significantly in the propiverine group, on average by 104 ml (V1: 262+/-132 ml. V2: 366+/-143 ml, P<0.001). The changes in bladder capacity during the first contraction and the maximum detrusor contraction in the verum group were both statistically significant. The bladder compliance documented a more pronounced increase under propiverine in comparison to placebo. Residual urine increased by 37+/-71 ml in the propiverine group, significantly more than in the placebo group (P=0.01). Sixty-three per cent of the patients expressed subjectively an improvement under propiverine in comparison with 23% of the placebo group. Expected anticholinergic adverse events occurred: dryness of the mouth (37% in the verum and 8% in the placebo group), accommodation disorders (28% and 2% respectively). Nausea, constipation, headache, dizziness, tiredness and palpitations were reported in almost comparable incidence rates between 3 and 13% in both treatment groups. Eight drop-outs were registered in the propiverine group (five due to adverse events) and three in the placebo group (one due to adverse events). The laboratory parameters revealed no changes. CONCLUSION: Propiverine proved its efficacy in detrusor hyperreflexia with regard to the urodynamic parameters of the maximal cystometric bladder capacity and detrusor contractility. Anticholinergic adverse events such as dryness of the mouth and accommodation disorders were considered being tolerable. The increase in residual urine reflects the therapeutically desired effect of detrusor relaxation because the majority of patients normally practise intermittent catheterisation for bladder emptying.     

Effect of partial bladder outlet obstruction on detrusor compliance, excitability and contractility in rats

OBJECTIVE: Partial bladder outlet obstruction (PBOO) is believed to change the functions of the detrusor, and can lead to an overactive detrusor (OD). The aim of this study was to investigate changes in bladder compliance, excitability and contractility after PBOO in rats. MATERIAL AND METHODS: PBOO was performed for 6 weeks in 20 Wistar rats, 13 of which (OD group) had an OD and seven of which (non-OD group) did not. Simultaneously, 10 rats that underwent sham operations (control group) were also studied. Bladder compliance and cystometric capacity were identified in vivo, but bladder compliance was detected without elimination of bladder capacity. Isolated bladder smooth muscle strip (BSMS) was dissected to determine excitability and contractility. RESULTS: After 6 weeks of PBOO, cystometric capacity and compliance were significantly higher than those in the control group. Compliance was 0.170+/-0.029 and 0.149+/-0.042 ml/cmH2O in the OD and non-OD groups, respectively, compared to 0.037+/-0.017 ml/cmH2O in the control group. The corresponding cystometric capacities were 3.66+/-0.490, 3.08+/-0.590 and 1.14+/-0.225 ml. The excitability in the OD group increased significantly compared to that in the non-OD and control groups. The tension threshold for BSMS contraction was lower in the OD group, and BSMS contracted more frequently at the same tension. The contractility of the BSMS in the OD group decreased significantly compared to that in the non-OD and control groups. CONCLUSIONS: PBOO can cause a higher cystometric capacity and compliance. After PBOO, there is a chance that an OD may develop. When this occurs, the detrusor excitability increases and contractility decreases.     

Role of sorbitol in the up-regulation of urinary bladder M(2) muscarinic receptors in streptozotocin-induced diabetic rats

This study investigated the role of sorbitol, a metabolic product of glucose, in the pathogenesis of rat diabetic cystopathy. Three-month-old male Wistar rats were divided into four groups: 1) normal controls; 2) rats rendered diabetic by streptozotocin; 3) rats fed with glucose; and 4) rats injected with sorbitol. The M(2) muscarinic receptor (M(2)-mAChR) protein and mRNA densities of the bladder tissue were measured by Western immunoblot and Northern blot, respectively. The streptozotocin-induced diabetic rats were then treated with ONO-2235, an aldose reductase inhibitor. The bladder M(2)-mAChR protein and mRNA were compared between the treated and untreated diabetic rats. The densities of M(2)-mAChR protein and mRNA in the bladder tissue were significantly increased in diabetic rats, and rats given either glucose or sorbitol (increases in receptor protein: 27.3 +/- 3.3, 19.8 +/- 2.3, and 18.0 +/- 2.1%; increases in mRNA: 39.6 +/- 3.7, 33.1 +/- 2.9, and 20.2 +/- 2.2%, respectively). When diabetic rats were treated with ONO-2235, the increases in bladder M(2)-mAChR protein and mRNA were significantly alleviated. The findings suggest that sorbitol plays a role in the pathogenesis of diabetic cystopathy in rats rendered diabetic by streptozotocin. Aldose reductase inhibitors may be useful in the treatment and prevention of diabetic cystopathy.     

Time dependent changes in diabetic cystopathy in rats include compensated and decompensated bladder function

PURPOSE: Diabetic bladder dysfunction is among the most common and bothersome complications of diabetes mellitus. While bladder filling and voiding problems have been reported, the precise functional changes in diabetic bladders remain unclear. We investigated time dependent changes in bladder function in streptozotocin induced diabetic rats. MATERIALS AND METHODS: Cystometrograms and detrusor muscle contractility were examined in male age matched control and diabetic Sprague-Dawley rats (Harlan, Indianapolis, Indiana) 3, 6, 9, 12 and 20 weeks after diabetes induction with streptozotocin. RESULTS: Diabetes decreased average body weight and increased bladder weight, capacity and compliance. Peak detrusor leak pressure increased gradually from weeks 3 to 6 to 9 in diabetic rats (mean +/- SEM 47.3 +/- 2.5, 50.8 +/- 3.0 and 56.0 +/- 3.6 cm H(2)O) and in controls (36.9 +/- 1.4, 37.7 +/- 1.5 and 41.6 +/- 1.81 cm H(2)O, respectively). However, at 12 and 20 weeks diabetic rats deviated strongly from this trend with peak detrusor leak pressure decreasing vs controls (41.6 +/- 2.8 and 37.3 +/- 0.9 vs 45.2 +/- 1.7 and 49.6 +/- 1.4 cm H(2)O, respectively) and post-void resting pressures increasing from 9-week levels vs controls (interactions p <0.0001). In contractility studies increased contractile force responses of diabetic animals to carbamylcholine chloride, potassium chloride, adenosine 5'-triphosphate and electric field stimulation peaked at 6 or 9 weeks but at 12 to 20 weeks they generally reverted toward those of controls (carbamylcholine chloride and electrical field stimulation interactions p = 0.0022 and 0.01, respectively). CONCLUSIONS: Diabetic bladders may undergo a transition from a compensated to a decompensated state and transition in the streptozotocin rat model may begin 9 to 12 weeks after induction.     

Depressed contractile responses to neurokinin A in idiopathic but not neurogenic overactive human detrusor muscle

OBJECTIVE: The role of tachykinins such as neurokinin A in regulating bladder function is unclear, but NK2 receptors seem to mediate contraction in the human bladder and it has been suggested that these peptides may have a role in the pathophysiology of bladder dysfunction. The present study investigates neurokinin receptor-mediated contractility of detrusor muscle in the idiopathic overactive and neurogenic overactive bladder and investigates the neurokinin receptor subtypes involved. METHODS: Human bladder was obtained from patients undergoing cystectomy (normal) or clam cystoplasty (idiopathic overactive) and from patients with spinal injuries (neurogenic overactive). Strips of isolated detrusor muscle were mounted in physiological Krebs-bicarbonate solution and cumulative concentration-response curves to 1 nM to 300 microM neurokinin A (NKA) were obtained in the absence and presence of neurokinin receptor antagonists, either the NK2 receptor-selective antagonist SR 48968 or the NK3 receptor-selective antagonist SB 223412. RESULTS: NKA evoked concentration-dependent contraction of normal, idiopathic, and neurogenic overactive detrusor strips. In idiopathic overactive detrusor muscle, NKA-induced contraction was significantly reduced relative to normal detrusor (0.031 +/- 0.005 mg/g, n = 11 versus 0.193 +/- 0.039 mg/g, n = 7). Sensitivity to the peptide was also significantly (p < 0.01) reduced in idiopathic overactive detrusor, with mean pEC50 values (concentration producing 50% maximal response) of 6.62+/-0.16 (n = 11) compared to 7.47+/-0.19 (n = 7) in normal detrusor. In contrast, NKA-induced responses of neurogenic overactive detrusor were similar to those in normal detrusor, with a mean maximum contraction of 0.199 +/- 0.036 mg/g (n = 10) and mean pEC50 value of 7.85+/-0.16 (n = 10). NKA curves in all groups were shifted to the right by the NK2 receptor-selective antagonist SR 48968 with high affinity, pK(B) values being similar in normal, idiopathic, and neurogenic overactive detrusor (8.85 + 0.08, n = 14; 8.97 +/- 0.13, n = 12; 8.73 +/- 0.12, n = 8, respectively). In contrast the NK3 receptor-selective antagonist SB 223412 had a minimal effect on NKA responses and affinity values were low (pK(B) 5.81 +/- 0.11, n = 12 in normal; 5.75 +/- 0.08, n = 12 in idiopathic overactive, and 5.77 +/- 0.13, n = 11 in neurogenic overactive). CONCLUSION: These data indicate that NKA-induced responses are impaired in detrusor muscle from idiopathic overactive human bladder, but not in detrusor muscle from neurogenic overactive bladder. The NK2 receptor subtype appears to mediate NKA responses in the normal, idiopathic overactive, and neurogenic overactive detrusor. This is important evidence suggesting a difference between the bladder pathophysiology observed in idiopathic versus neurogenic overactive detrusor.