Adipose tissue-derived stem cells ameliorate diabetic bladder dysfunction in a type II diabetic rat model

Diabetes mellitus is associated with a broad constellation of voiding complaints that are often multifactorial and resistant to currently available therapies. The leading causes of diabetic bladder dysfunction (DBD) include alterations in the bladder smooth muscle, neuronal degeneration, and urothelial dysfunction. Adipose tissue-derived stem cells (ADSCs), a type of mesenchymal stromal cells, have shown promise as a novel tissue regenerative technique that may have utility in DBD. The aim of this study is to determine the efficacy and mechanism by which ADSCs may ameliorate DBD in rats fed a high-fat diet and treated with low-dose streptozotocin to induce type II diabetes. Improved voiding function was noted in ADSCs-treated rats as compared with phosphate-buffered saline-treated rats. Though some ADSCs differentiated into smooth muscle cells, paracrine pathway seems to play a main role in this process, thus resulting in reduction of apoptosis and preservation of "suburothelial capillaries network."     

糖尿病大鼠膀胱肾上腺素能α_1受体表达改变

目的研究糖尿病大鼠膀胱结构功能的改变及其肾上腺素能α1受体及其亚型的表达改变,并探讨其意义。方法采用1%链脲佐菌素(STZ)建立糖尿病大鼠的模型,实验分为正常对照组和糖尿病组。分别于2周、4周、6周进行在体充盈性膀胱测压评估膀胱功能,处死动物后取膀胱组织标本常规HE染色观察膀胱逼尿肌病理组织学变化,并采用Western blot与免疫荧光检测α1受体亚型(α1A受体与α1D受体)的表达改变。结果糖尿病大鼠体重减轻,尿量和膀胱湿重增加;充盈性膀胱测压检查结果显示糖尿病大鼠膀胱容量、顺应性、逼尿肌压力上升,残余尿量明显增加,排尿效率明显降低;常规HE染色光镜下观察可见糖尿病大鼠膀胱逼尿肌肌束进行性结构松散、紊乱,甚至出现肌束断裂。Western blott结果显示α1A受体及α1D受体的表达在逼尿肌中表达量随病程进行性下降,糖尿病组与正常对照组间对比差异有统计学意义。免疫荧光结果显示糖尿病膀胱实验组α1A受体和α1D受体灰度值均较相应对照组减少,且随病程进行性减少。结论糖尿病大鼠早期即可出现膀胱逼尿肌形态学和功能的改变,糖尿病膀胱中的α1-AR表达存在负相关关系,提示糖尿病可引起膀胱部位α1-AR表达减少。α1-AR表达减少可能是引起糖尿病膀胱顺应性增加,残余尿量增加的影响因素之一。     

Afferent fibers of the hypogastric nerves are involved in the facilitating effects of chemical bladder irritation in rats.

To evaluate the role of bladder afferent fibers in the hypogastric nerves (HGN) in modulation of the micturition reflex induced by chemical bladder irritation, voiding behavior, continuous cystometry, and spinal c-fos expression following intravesical acetic acid instillation were investigated in rats with or without HGN transection. Voiding behavior and continuous cystometry were examined in unanesthetized conscious rats. Following chemical bladder irritation, a significant increase in urinary frequency associated with a marked decrease in the voided volume per micturition, was noted in control rats with the intact HGN, but not in HGN-transected rats. Continuous infusion of acetic acid in control rats elicited irritative bladder responses characterized by a marked decrease in the intercontraction interval and a marked increase in maximal vesical pressure, both of which were absent in capsaicin-desensitized rats. HGN transection prevented the decrease in the intercontraction interval but not an increase in maximal vesical pressure following chemical bladder irritation. Compared with saline infusion, acetic acid infusion caused a significant increase in c-fos expression at L(1) and L(6) of the spinal cord, and HGN transection significantly reduced c-fos expression in the dorsal horn of the spinal cord at L(1) but not at L(6). These results suggest that capsaicin-sensitive bladder afferent fibers in the HGN, which travel through the rostral lumbar spinal cord, have a role in urinary frequency caused by chemical bladder irritation.     

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.     

人脐带间充质干细胞不同部位移植对压力性尿失禁治疗作用的研究

目的研究尿道周围及坐骨神经近端移植人脐带间充质干细胞（hUCMSCs）是否可以提高压力性尿失禁大鼠的尿道闭合压。改善其储尿能力。方法模拟绝经和产伤构建压力性尿失禁大鼠模型,并用漏尿点压力（LPP）、最大膀胱容积（MCC）及“模拟喷嚏”实验进行检测。将hUCMSCs分别注射移植到压力性尿失禁大鼠的尿道周围及坐骨神经近端。1个月后再次检测漏尿点压力及最大膀胱容积。结果移植后1个月,尿道周围治疗组与尿道周围模型组MCC差值差异无统计学意义（P〉0．05）;而尿道周围治疗组LPP增高,尿道周围模型组LPP降低,两组差值差异有统计学意义（P〈0．01）。移植后1个月．坐骨神经治疗组MCC和LPP与坐骨神经模型组相比,其差值差异均无统计学意义（P值均〉0．05）。结论人脐带间充质干细胞注射移植到尿道周围可以提高压力性尿失禁大鼠的尿道闭合压,但不能改善其储尿能力;而移植到坐骨神经近端短期内不能改善压力性尿失禁大鼠的储尿能力。     

Role of protein kinase C in central muscarinic inhibitory mechanisms regulating voiding in rats

To evaluate the role of protein kinase C in central muscarinic mechanisms regulating voiding, cystometry was performed in conscious rats. Oxotremorine methiodide, a muscarinic agonist was injected i.c.v. in a dose (0.1 microg/rat) shown previously to alter voiding function. Oxotremorine methiodide was also tested after i.c.v. injection of chelerythrine chloride (a protein kinase C inhibitor, 2 microg/rat) or 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7, a protein kinase inhibitor, 5 nmol/rat). In untreated rats, oxotremorine methiodide elicited a bimodal response consisting of an initial increase in bladder capacity, maximal voiding pressure, pressure threshold and post voiding intravesical pressure, but reduced voiding efficiency and bladder compliance. The second response consisted of a decrease in bladder capacity and bladder compliance, increases in maximal voiding pressure and post voiding intravesical pressure, but no change in pressure threshold or voiding efficiency. However, approximately 20 min after pre-treatment with chelerythrine chloride or H-7 in doses that did not alter voiding function, oxotremorine methiodide decreased bladder capacity, increased maximal voiding pressure, but did not change pressure threshold or voiding efficiency. These results indicate that inhibitory and facilitatory muscarinic mechanisms in the brain that control voiding function involve different second messenger systems. Inhibitory mechanisms which are blocked by chelerythrine chloride or H-7 must involve protein kinase C and normally be inactive because the protein kinase inhibitors alone did not alter voiding. On the other hand, facilitatory muscarinic mechanisms which previous studies showed were tonically active are not mediated by chelerythrine chloride or H-7 sensitive signaling pathways.     

不同灌注速度及方法对大鼠膀胱容量、压力及神经传入电活动测定的影响

目的:探讨不同灌注速度及方法对大鼠膀胱容量、压力及神经传入电活动测定的影响。方法:SD雌性大鼠随机分为2组,分别选用尿道插管法及膀胱顶造瘘法,以50、100、200和400μL/min的速度进行灌注,以尿动力仪观察灌注过程中膀胱容量及压力的变化,以多通道生理记录仪检测灌注过程中膀胱神经传入电活动的变化。结果:采用插管法进行灌注测得最大放电频率,其随速度的升高呈上升趋势;膀胱漏尿点压(BLPP)和最大膀胱排尿压(MVP)随着灌注速度的升高而增大;各灌注速度下膀胱最大容量(MBC)无显著变化。造瘘法以各速度测得最大放电频率均无显著变化;其MBC随速度升高呈下降趋势,且在200及400μL/min灌注时显著降低;其BLPP及MVP无明显变化。2种方法相比,放电频率基线值无显著差异,以100、200和400μL/min进行灌注时造瘘法测得的膀胱最大放电频率均低于插管法;以不同速度灌注,造瘘法测得的MBC均比插管法小;而以50和100μL/min进行灌注时,造瘘法测得的压力比插管法高。结论:插管法以不同速度进行灌注并未对膀胱容量造成明显变化,但其膀胱压力及神经放电频率随速度升高,使用此法应根据研究目的选择灌注速度;采用造瘘法在200及400μL/min的灌注速度时,膀胱容量明显减少,故采用该法时建议以200μL/min的速度进行灌注。     

糖尿病性勃起功能障碍大鼠阴茎和脊髓nNOS及AchE表达的变化

目的：观察大鼠糖尿病性勃起功能障碍（ED）与腰骶段脊髓和阴茎神经源性一氧化氮合酶（nNOS）和乙酰胆碱酯酶（AchE）阳性神经元或神经纤维变化的相关性。方法：注射链脲佐菌素建立糖尿病大鼠模型,4周和12周后注射阿扑吗啡（APO）进行大鼠阴茎勃起功能实验,取大鼠阴茎和腰骶段脊髓,用ABC免疫组织化学法和组织化学法分别显示nNOS和AchE阳性神经元或神经纤维。结果：与对照组相比,糖尿病4周时,大鼠阴茎勃起次数无显著性差异;12周时显著性减少;糖尿病4周时,脊髓和阴茎nNOS和AchE阳性神经元或神经纤维均无显著变化,而12周时均显著减少。结论：糖尿病性ED的出现伴随脊髓和阴茎内NO和乙酰胆碱的减少。     

Bladder afferent pathway and spinal cord injury: possible mechanisms inducing hyperreflexia of the urinary bladder

Lower urinary tract dysfunction is a common problem in patients with spinal cord injury (SCI). Since the coordination of the urinary bladder and urethra is controlled by the complex mechanisms in spinal and supraspinal neural pathways, SCI rostral to the lumbosacral level disrupts voluntary and supraspinal control of voiding and induces a considerable reorganization of the micturition reflex pathway. Following SCI, the urinary bladder is initially areflexic. but then becomes hyperreflexic because of the emergence of a spinal micturition reflex pathway. Recent electrophysiologic and histologic studies in rats have revealed that chronic SCI induces various phenotypic changes in bladder afferent neurons such as: (1) somal hypertrophy along with increased expression of neurofilament protein; and (2) increased excitability due to the plasticity of Na+ and K+ ion channels. These results have now provided detailed information to support the previous notion that capsaicin-sensitive, unmyelinated C-fiber afferents innervating the urinary bladder change their properties after SCI and are responsible for inducing bladder hyperreflexia in both humans and animals. It is also suggested that the changes in bladder reflex pathways following SCI are influenced by neural-target organ interactions probably mediated by neurotrophic signals originating in the hypertrophied bladder. Thus, increased knowledge of the plasticity in bladder afferent pathways may help to explain the pathogenesis of lower urinary tract dysfunctions after SCI and may provide valuable insights into new therapeutic strategies for urinary symptoms in spinal cord-injured patients.     

Innervation of the Epithelium and Lamina Propria of the Urethra of the Female Rat

The aim of this study was to characterize the number, type and distribution of immunochemically identified nerves in epithelium and lamina propria of the female rat urethra. Urethras from female Sprague–Dawley rats (n = 12) were fixed, frozen and sectioned (8 μm). Standard immunohistochemical techniques were used to identify putative nerves using the following antibodies: calcitonin gene related peptide (cgrp), neuronal nitric oxide synthase (nNos), tyrosine hydroxylase (TH) and vesicular acetylcholine transporter (vacht). The number, distribution and characteristics of all immunoreactive (IR) structures adjacent to the urethral epithelium and in the lamina propria was assessed. In the bladder, few cgrp-IR and vacht-IR fibers were associated with the urothelium or suburothelium of the lateral wall. In contrast, large numbers of vacht-IR, nNos-IR and cgrp-IR fibers were found close to the epithelium and subepithelium of the bladder neck and throughout the urethra. The number of cgrp-IR fibers was significantly higher in the urethra in comparison with the bladder neck. A population of undescribed cgrp-IR cells associated with the bladder neck and proximal urethra has been characterized. Each of these cells appears to be associated with a nerve fiber. In the distal urethra, the number of peptidergic fibers penetrating the epithelium was significantly higher than the rest of the urethra. Clearly, this study has revealed a highly complex and heterogeneous network of putative afferent nerves fibers along the length of the urethra. These structural specializations need to be taken into account when probing the different functions of the urethra. Anat Rec, 302:201–214, 2019. © 2018 Wiley Periodicals, Inc.     

Hypoxia preconditioning attenuates bladder overdistension-induced oxidative injury by up-regulation of Bcl-2 in the rat

We explored whether hypoxic preconditioning minimizes oxidative injury induced by overdistension/emptying in the rat bladder. For hypoxic preconditioning, female Wistar rats were placed in a hypobaric chamber (380 Torr) 15 h day⁻¹ for 28 days. Overdistension was induced by infusion of two times the threshold volume of saline into the bladder and was maintained for 1 or 2 h, followed by drainage/emptying. During overdistension (ischaemia) and emptying (reperfusion) periods, a bursting increase of reactive oxygen species (ROS) from the bladder was originated from the large numbers of infiltrating leucocytes and scattered resident cells, including urothelial, submucosal, and smooth muscle cells. ROS impaired the voiding function by a reduction of bladder afferent and efferent nerve activity and bethanecol- or ATP-induced detrusor contraction. ROS enhanced pro-apoptotic mechanisms, including increases in the Bax/Bcl-2 ratio, CPP32 expression, and poly(ADP-ribose) polymerase (PARP) fragments with subsequent apoptotic cell formation in the insulted bladders. Hypoxia preconditioning up-regulated Bcl-2 expression in the bladder and significantly reduced the levels of ROS and apoptosis detected in the overdistension/emptying bladders and preserved partial voiding function. Bcl-2 up-regulation by hypoxia preconditioning contributes protection against overdistension/emptying-induced oxidative stress and injury in the bladder.     

Expression of vascular endothelial growth factor in the lower urinary tract in rats after castration and estrogen administration

OBJECTIVE: To evaluate quantitatively, by means of immune histochemistry, the expression of the vascular endothelial growth factor (VEGF) in the bladder, vesicourethral junction, and urethra in normal, castrated adult rats and under estrogen administration. DESIGN: Sixty adult virgin rats (Rattus norvergicus albinus, Rodentia, Mammalia) from the CEDEME-UNIFESP Animal House were used. Rats were divided into three groups. Group I comprised noncastrated rats, group II comprised oophorectomized rats, and group III comprised castrated rats administered 17beta-estradiol in the form of subcutaneous implants at the dose of 0.18 mg/implant for 30 days. After performing standard immunohistochemistry procedures, the intensity of the dark-brown color was used as the cytoplasmic protein expression of VEGF. Cells without this coloration or weakly stained were considered negative. percentile of VEGF expression was obtained by counting 1,000 cells per slide and establishing the ratio between positive and total cells. RESULTS: The VEGF expression was uniform and similar along the urinary tract in group I. After castration, protein expression was almost absent in the bladder and was low in the vesicourethral junction and urethra. With estrogen replacement, very little of the expression was recovered in the bladder, and the reaction became evident in the vesicourethral junction and urethral sections. CONCLUSIONS: The present study implies a potential relationship between VEGF and urinary tract physiology. The results suggest that there are quantitative differences in VEGF expression in these tissues depending on steroid hormone status.     

c-fos expression in bladder-specific spinal neurons after spinal cord injury using pseudorabies virus

PURPOSE: c-fos expression in spinal neurons that are activated by lower urinary tract stimulation are not organ specific. In this experiment, we demonstrated changes of c-fos expression in bladder-specific preganglionic neurons (PGNs) and interneurons using pseudorabies virus (PRV). MATERIALS AND METHODS: Forty Sprague-Dawley rats were used. We identified the neuronal pathway associated with the bladder by injecting PRV into the detrusor. An immunohistochemical method was used to stain Fos-protein encoded by the c-fos gene. Immunofluorescent staining for PRV was performed to evaluate changes in bladder-specific spinal neurons. RESULTS: Immunofluorescent staining with choline acetyltransferase (ChAT) revealed that the sacral parasympathetic nucleus (SPN) regions contained 9.8 PGNs/section. In rats with chronic spinal cord injury by intravesical saline instillation, 82.4+/-10.3% of PGNs in SPN exhibited Fos-immunoreactive (IR). Two and a half days after PRV infection, PRV-IR PGNs were observed at 5.4 PGNs/section, and 2.7+/-1.6% of them exhibited Fos-IR. Unlike ChAT-IR PGNs, PRV-IR PGNs are bladder-specific neurons and PRV-IR and Fos-IR cells found in the back of PRV-IR PGNs are bladder-specific interneurons. Three days after PRV infection, we observed many PRV-IR and Fos-IR cells in the dorsal commissure. These neurons are interneurons distributed in the bladder. CONCLUSION: We confirmed that in chronic spinal cord injury, the patterns of c-fos expression in bladder-specific spinal neurons were similar to those in voiding-reflex related spinal neurons, which had already been demonstrated earlier. We believe that our methodology can be applied to study interactions between voiding and other organs as well, such as the urethra and prostate.     

模拟人体尿道插管法行小鼠尿动力学检测

 目的: 国际上传统的小鼠尿动力学检测方法为膀胱造瘘法。该传统方法破坏膀胱连续性,与临床上广泛采用的经尿道法有明显的差异。本研究寻找到合适的小鼠导尿管材,拟探讨模拟人体经尿道插管法行小鼠尿动力学检测的优势和应用价值。方法: 雌性小鼠8只,选择小儿留置针软芯进行导尿,并作为测压管和膀胱灌注管,经三通外接微量泵以及压力感受器。直肠测压采用硬膜外麻醉导管,外套乳胶手套小指末端一截制成球囊,然后导入小鼠直肠。结果: 该方法成功收集到以下尿动力学指标:膀胱基础压力(BBP)、膀胱漏尿点压(BLPP)、最大排尿压(MVP)、膀胱最大容量(MBC)、残余尿量(PVR)、排尿量(VV)、排尿效率(EV)和膀胱顺应性(BC)。结论: 本研究首次成功模拟人体经尿道插管法,实现小鼠尿动力学检测,成功避免膀胱造瘘对小鼠尿动力学的影响,检测后的小鼠能够长期生存,可以顺利进行后续分子和基因实验。     

白藜芦醇对糖尿病大鼠心功能障碍及酸性鞘磷脂酶-神经酰胺通路的影响

目的:观察白藜芦醇(RSV)对糖尿病大鼠心功能障碍的影响并探讨其与酸性鞘磷脂酶-神经酰胺通路的关系。方法:通过一次性腹腔注射小剂量链脲佐菌素(STZ;30 mg/kg)联合高脂饮食饲养12周构建2型糖尿病(T2DM)大鼠模型。实验分为正常对照(control)组、T2DM组、T2DM+RSV组(灌胃给予糖尿病大鼠白藜芦醇100 mg·kg~(-1)·d~(-1))和RSV组(正常大鼠灌胃给予同等容量RSV),共灌胃12周,每周称量体重并调整给药剂量。实验结束后,釆用小动物M型超声检测模型大鼠心脏功能、形态和结构的变化;颈动脉插管检测血流动力学变化;生化方法检测血清中糖、脂水平以及心脏组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量;油红O染色和天狼星红染色分别观察心脏组织中脂肪堆积和心肌纤维化情况;高效液相质谱法检测心脏组织中神经酰胺(ceramide)含量;Western blot检测酸性鞘磷脂酶(ASMase)和过氧化物酶增殖体激活受体γ辅激活因子1α(PGC~(-1)α)的蛋白表达。结果:T2DM组大鼠空腹血糖、甘油三酯、胆固醇及低密度脂蛋白胆固醇水平均较control组显著升高,心功能显著降低(P0.05);T2DM组大鼠心脏组织中脂肪堆积、MDA含量显著增加(P0.05),SOD活性、ATP水平和PGC~(-1)α蛋白表达均显著降低(P0.05),且出现明显心肌纤维化;给予白藜芦醇治疗12周可显著改善以上指标的异常变化,同时,显著下调糖尿病大鼠升高的心肌ASMase蛋白和ceramide水平。结论:白藜芦醇可显著改善糖尿病诱导的大鼠心功能障碍和心肌纤维化,其机制可能与抑制ASMase-ceramide通路有关。     

Caveolin-1在高盐饮食损伤糖尿病大鼠血管中的作用

目的:观察1型糖尿病(DM)大鼠给予高盐饮食后内皮细胞功能障碍的可能机制。方法:SD大鼠(150~180 g)60只,腹腔注射链唑霉素(70 mg/kg),3 d后空腹血糖≥16.7 mmol/L为1型DM大鼠。正常大鼠和DM大鼠分别给予正常饮食和高盐饮食(8%Na Cl)6周。检测肠系膜动脉舒张功能,Western blot技术检测血管中Akt、内皮型一氧化氮合酶(e NOS)、caveolin-1(Cav-1)等蛋白的水平。结果:高盐饮食DM大鼠收缩压显著高于DM组,其肠系膜动脉乙酰胆碱和胰岛素的舒张作用显著下降(P0.01)。Akt、p-e NOS和NO水平均显著低于DM组(P0.01),Cav-1显著增高(P0.01)。结论:1型糖尿病大鼠高盐饮食血管功能障碍可能与抑制内皮细胞Akt激活及增强Cav-1表达导致的e NOS活性下降有关。     

IkB激酶在糖尿病性大鼠ED中的作用

目的探讨IkB激酶(Ik kinases,IKK)在糖尿病(diabetes mellitus,DM)性阴茎勃起功能障碍(erectiledy sfunction,ED)中的可能作用。方法注射链脲佐菌素建立糖尿病大鼠模型,分别在注射8周和12周后观察阴茎勃起次数,取大鼠阴茎,Western Blot方法检测IKK蛋白量的变化,ABC免疫组织化学方法检测阴茎IKK的分布和表达。结果 Dm大鼠的阴茎勃起次数明显低于对照组(P0.01),随病程延长降低;Western Blotting结果显示,DM组阴茎IKK蛋白量明显高于正常对照组(P0.01),12周DM组明显高于8周DM组(P0.05);IKK主要分布于阴茎血管、阴茎背神经,与对照组比较,DM组平均光密度值明显上调并随病程延长而上调。结论 DM大鼠阴茎IKK蛋白量的上调可能通过作用于阴茎内的血管、神经参与了糖尿病性ED发病。     

Urinary bladder and urethral responses to pelvic and hypogastric nerve stimulation and their relation to vasoactive intestinal polypeptide in the anaesthetized dog

The effects on the urinary bladder and urethra of pelvic and hypogastric nerve stimulation and their relation to vasoactive intestinal polypeptides (VIP) were investigated in the anaesthetized dog. Both pelvic and hypogastric nerve stimulation elicited a twofold increase in urinary bladder blood flow and a clear-cut increase in bladder venous effluent VIP concentration. Hypogastric nerve stimulation induced an initial, partly alpha-adrenergic and partly non-adrenergic, non-cholinergic, contraction of the urinary bladder followed by a relaxation. The urethra response was a maintained alpha-adrenergic contraction. Pelvic nerve stimulation elicited a bladder contraction with an initial non-cholinergic peak, whereafter the bladder pressure was maintained at a lower level, an effect which was mainly cholinergic in origin. The urethral response was an initial non-adrenergic, non-cholinergic contraction followed by a maintained cholinergic contractile response. Afferent pelvic nerve stimulation led to an efferent activity that seemed to be a combination of activity in pelvic and hypogastric pathways to the urinary bladder and the urethra. VIP (10 nmol) injected i.v. induced a relaxation of the urinary bladder and the urethra, together with a fall in systemic blood pressure. However, despite high plasma concentrations, no vasodilation was elicited in the urinary bladder. Thus, the main target for the VIP release during pelvic and hypogastric nerve stimulation is probably not the bladder vasculature, but instead perhaps the bladder smooth muscle proper.     

Bone marrow-derived cells implanted into radiation-injured urinary bladders reconstruct functional bladder tissues in rats

The purpose of this study was to determine whether bone marrow-derived cells implanted into radiation-injured urinary bladders could reconstruct functional bladder tissues. The pelvic region of anesthetized female Sprague-Dawley (SD) rats was irradiated with 2 Gy once a week for 5 weeks. After the last irradiation, the rats were maintained for 2 weeks. Bone marrow cells were harvested from the femurs of donor male green fluorescence protein (GFP)-transfected SD rats and cultured for 7 days. Two weeks after the last radiation exposure, the cultured adherent, proliferating bone marrow-derived cells were implanted into the walls of irradiated urinary bladders. For controls, cell-free solutions were similarly injected. Four weeks after donor cell or control implantations, cystometric, histological, and immunohistochemical investigations were performed. Two weeks after the last irradiation, the smooth muscle layers and nerve fibers of the irradiated urinary bladders were disorganized. The proportions of smooth muscle layer and nerve fiber areas were significantly decreased compared with sham-irradiated urinary bladders. In addition, the remaining smooth muscle cells within the irradiated urinary bladders expressed P4HB, an indicator of collagen synthesis. In the cystometric investigations, the voiding interval of irradiated rats was irregularly prolonged, 7.92±1.09?min, and the residual volume, 0.13±0.03?mL, was significantly higher compared with the sham-irradiated rats (5.50±0.43?mL and 0.05±0.01?mL). After 4 weeks, the smooth muscle layers and nerve fibers in the cell-free control urinary bladders remained similar to the preimplanted irradiated urinary bladders; however, the cell-implanted urinary bladders contained reconstructed smooth muscle layers and nerve fibers, the proportions of each were significantly higher than those in the cell-free injected controls. The expression of P4HB within the cell-implanted urinary bladders decreased. Some GFP-positive implanted cells differentiated into smooth muscle- and nerve-like cells and became organized into the reconstructed tissues. The voiding interval of the cell-implanted rats, 5.46±0.33?min, was regular and similar to that of the sham-irradiated rats, and significantly less than that of the cell-free injected controls, 7.39±0.54?min. The residual volume, 0.04±0.01?mL, was similar to that of the sham-irradiated rats and significantly decreased compared with that of the cell-free injected controls, 0.15±0.05?mL. Therefore, the implantation of bone marrow-derived cells is a potentially useful treatment for radiotherapy-induced urinary dysfunctions.     

8周游泳运动对2型糖尿病大鼠周围神经病变的影响

 目的： 探讨长期游泳运动对2型糖尿病大鼠周围神经病变的影响及可能机制。方法: 雄性Wistar大鼠高糖高脂饲料喂养联合链脲佐菌素注射制备成T2DM大鼠模型后,随机分为空白对照组（C组）、单纯运动组（CE组）、糖尿病对照组（DM组）和糖尿病运动组（DME组）。CE组和DME组进行8周游泳训练（6 d/week）,第1周前3 d练习时间分别为20、30和45 min,第4天起每天持续游泳60 min。运动8周后测定各组大鼠坐骨神经的传导速度（MNCV）,以及该组织中肿瘤坏死因子α（TNF-α）、白细胞介素6（IL-6）、C反应蛋白（CRP）的含量,观察其形态结构。结果: 实验末,与DM组相比,DME组的MNCV明显提高（P<0.05）,坐骨神经组织中TNF-α、IL-6和CRP水平均有所降低,但差异无统计学意义（P>0.05）。DM组坐骨神经光镜下可见明显的损伤,经运动干预后病变程度减轻。结论: 8周游泳运动可提高MNCV,减轻DM造成的神经损伤,对周围神经起保护作用,其机制可能与减轻炎症反应有关。