兔阴茎海绵体平滑肌细胞的体外培养及其生物学特性

目的 :研究体外培养的新西兰白兔阴茎海绵体平滑肌细胞的生物学特性。　方法 :采用组织块培养法 ,对兔阴茎海绵体平滑肌细胞进行活细胞观察 ,并测定其细胞生长曲线、贴壁率、细胞分裂指数。　结果 :①兔阴茎海绵体平滑肌细胞为梭形 ,呈长轴平行排列 ,具有明显的方向性 ;②体外贴壁快 ,生长迅速 ,体外培养的阴茎海绵体平滑肌细胞在合适的传代条件和比例下能够生存并保持其稳定的生物学特性。　结论 :体外培养的兔阴茎海绵体平滑肌细胞模型可用于检测某些药物对阴茎勃起的影响。     

人阴茎海绵体平滑肌细胞的原代培养及鉴定

目的　为研究人阴茎勃起功能提供方便的实验材料。　方法　取新鲜尸体阴茎海绵体平滑肌细胞 ,用含 2 0 %人AB型血清的DMEM液作体外原代培养 ,并以免疫组化法鉴定。　结果　经 10～ 14d培养后 ,6个培养瓶内均铺满梭状细胞 ,免疫组化法鉴定确认为人阴茎海绵体平滑肌细胞。　结论　人阴茎海绵体平滑肌细胞可在体外条件下生长传代 ,并可能成系 ,为阴茎勃起功能的研究提供方便的材料     

阴茎海绵体平滑肌细胞培养进展

阐述阴茎海绵体平滑肌细胞（CCSM）培养对目前研究勃起功能障碍的重要性。比较CCSM与其他平滑肌细胞培养的差异,同时比较两种不同的CCSM培养方法结果的异同,为研究勃起功能障碍培养CCSM方法的选择提供参考。     

家兔阴茎海绵体平滑肌细胞体外培养方法对比研究

目的　探索更好、更方便的家兔阴茎海绵体平滑肌细胞体外培养方法。方法　分别采用组织块法、酶消化法、组织块 酶消化法对家兔阴茎海绵体平滑肌细胞进行培养 ,在倒置显微镜下对培养过程的细胞分别作了生长情况及形态学观察。用HE染色、MTT法分别描绘原代培养细胞的生长曲线、细胞分裂指数曲线 ;用倒置显微镜观察活细胞的贴壁过程 ,计数法测定细胞贴壁率。结果　组织块法及酶消化法培养的细胞其生长状况和形态学各有自己的特点。组织块法的细胞生长慢 ,培养时间相对较长 ,纯度相对较高 ,原代培养细胞生长速度快 ,但由于该法消化时间不易掌握 ,常影响其成功率 ,多数细胞呈梭形 ,细胞的密度高 ,原代培养时间为 7～ 10d。结论　每种培养方法都有各自的优缺点。我们可根据实验的需要而选择不同的方法或联合培养     

兔阴茎海绵体平滑肌细胞的体外培养及其生物学特性

目的；研究体外培养的新西兰白兔阴茎海绵体平滑纲细胞的生物学特性。方法：采用组织块培养法，对兔阴茎海绵体平滑肌细胞进行活细胞观察，并测定其细胞生长曲线，贴壁率，细胞分裂指数。结果：（1）兔阴茎海绵体平滑肌细胞为梭形，呈长轴平行排列，具有明显的方向性；（2）体外贴壁快，生长迅速，体外培养的阴茎海绵体平滑肌细胞在合适的传代条件和比例下能够生存并保持其稳定的生物学特性。结论：体外培养的兔阴茎海绵体平滑肌细胞模型可用于检测某些药物对阴茎勃起的影响。     

新西兰兔尿道海绵体平滑肌细胞的原代培养及鉴定

目的 为构建新西兰兔组织工程尿道提供种子细胞。方法 取新西兰兔阴茎头，用含10％胎牛血清的高糖DMEM作体外原代培养，并行免疫组织化学法鉴定。结果经10～14d培养后，培养瓶底铺满梭状细胞，免疫组织化学法鉴定确认为兔尿道海绵体平滑肌细胞。结论兔阴茎头平滑肌细胞可在体外条件下生长传代、扩增，可作为构建组织工程尿道的种子细胞。     

SD大鼠阴茎平滑肌细胞的获取和体外培养

目的 研究SD大鼠阴茎平滑肌细胞体外培养方法和生物学特性.方法 采用贴壁组织块培养法和酶消化培养法,对SD大鼠阴茎海绵体平滑肌细胞进行活细胞观察.结果 (1)SD大鼠阴茎海绵体平滑肌细胞为梭形,呈长轴平行排列,具有明显的方向性;体外贴壁快,生长迅速,体外培养的阴茎海绵体平滑肌细胞在合适的传代条件和比例下能够生存并保持其稳定的生物学特性.(2)酶消化培养法获得细胞的纯度高,接种后细胞生长快.贴壁组织块培养法操作简单易于掌握.结论 贴壁组织块培养法和酶消化培养法均可以获得平滑肌细胞,方法均方便可行.我们可根据实验的需要选择不同的方法.     

实验性高脂免体外培养阴茎海绵体平滑肌细胞凋亡的研究

目的观察高脂诱导的血管性ED家兔阴茎海绵体平滑肌(Corpus Cavernosum Smooth Muscle,CCSM)细胞形态、结构变化及高脂对CCSM细胞凋亡、增殖的影响。方法雄性新西兰家兔10只,随机分为模型组和对照组,每组各5只。模型组为采用经高脂、高胆固醇饮食结合球囊导管扩张双侧髂内动脉建立、鉴定的血管性ED模型;对照组喂以正常饮食。8周后切取阴茎CCSM组织观察并做体外细胞培养。经处理后分别在光镜、透射电镜下观察,流式细胞仪检测细胞凋亡,MTT比色法观察细胞增殖活性,RT-PCR法研究Caspase-3 mRNA的表达情况,免疫荧光法检测Caspase-3活性。结果与对照组相比,模型组光镜和电镜下CCSM细胞内含较多脂质囊泡,线粒体、内质网等细胞器出现损伤,凋亡小体明显增多。流式细胞仪检测证实模型组CCSM细胞凋亡率较对照组明显增高(1.44±0.20%Vs5.96±1.60%,P<0.01)。MTT比色法显示高脂对CCSM的增殖有明显抑制作用(模型组与对照组A值分别为:0.52±0.08Vs1.42±0.04,P<0.01)。模型组的Caspase-3 mRNA表达和活性值均显著高于对照组(0.74±0.00Vs0.65±0.00,P<0.01;活性值0.03±0.00Vs0.01±0.00,P<0.05)。结论高脂、高胆固醇饮食可严重影响CCSM结构,促进CCSM细胞凋亡并抑制其增殖。CCSM细胞凋亡/增生的失衡可能是高脂导致ED发生发展的重要病理环节。     

体外分离培养兔阴茎海绵体平滑肌细胞的纯度分析

目的比较和评价不同条件下体外培养兔阴茎海绵体平滑肌细胞的纯度。方法应用胶原酶消化法和组织贴块法分离培养幼兔海绵体平滑肌细胞。差速贴壁法纯化海绵体平滑肌细胞。采用α-平滑肌肌动蛋白(α-SM-actin)和肌球蛋白(Myosin)免疫荧光鉴定海绵体平滑肌细胞,波形蛋白(Vimentin)衬染检测成纤维细胞。流式细胞仪检测海绵体细胞表达α-SM-actin的阳性率,比较不同培养条件下海绵体平滑肌细胞的纯度。结果体外培养的海绵体来源细胞在荧光显微镜下对α-SM-actin和Myosin仅有少量表达,随传代次数的增加,细胞表达α-SM-actin和Myosin的阳性率进一步降低。流式细胞仪检测酶消化法和贴块法原代培养的海绵体平滑肌细胞的纯度分别为16.91%和11.13%。经差速贴壁纯化后第1代海绵体平滑肌细胞的纯度分别提高到26.88%和21.98%。Vimentin免疫荧光检测到大量阳性表达。结论目前常规方法体外分离、培养的海绵体平滑肌细胞纯度较低,大量海绵体间质来源的成纤维细胞混杂生长,差速贴壁法可在一定范围内提高海绵体平滑肌细胞的纯度。     

兔骨髓间充质干细胞的分离、培养与鉴定

目的建立一种兔骨髓间充质干细胞（Mesenchymal stem cell，MSC）体外分离培养、扩增及鉴定的方法。方法骨髓穿刺法抽取新西兰白兔髂骨骨髓5ml，应用密度梯度离心法分离纯化MSC并进行体外扩增，倒置显微镜下观察原代及传代细胞的形态、生长情况，计数细胞数目，绘制细胞乍长曲线。HE染色光镜观察细胞形态，采用CD44及CD34抗体进行间接免疫荧光标记鉴定培养的干细胞。结果成功建立了兔MSC体外分离及培养扩增的方法。生长动力学分析发现，传代细胞随传代次数的增加其增殖能力逐渐下降，第3～5代细胞增殖能力强，生长旺盛。所分离培养的细胞均表达CD44，不表达CD34。结论在体外采用密度梯度离心及贴壁培养法可获得高纯度的兔骨髓间充质干细胞，第3～5代细胞增殖能力强，可用于进一步的研究工作。     

Expression of smooth muscle actin in osteoblasts in human bone.

It is well known that certain connective tissue cells (viz., dermal fibroblasts) can express the gene for a muscle actin--alpha-smooth muscle actin--and can contract. This process contributes to skin wound closure and is responsible for Dupuytren's contracture. The objective of this study was to determine if human osteoblasts can also express the gene for alpha-smooth muscle actin. Immunohistochemistry using a monoclonal antibody for alpha-smooth muscle actin was performed on human cancellous bone samples obtained from 20 individuals at the time of total joint arthroplasty. The percentages of resting and active osteoblasts on the bone surfaces containing this muscle actin isoform were evaluated. Explants of human bone were also studied for the expression of alpha-smooth muscle actin in the tissue and in the outgrowing cells with time in culture. Western blot analysis was performed to quantify the alpha-smooth muscle actin content of the outgrowing cells relative to smooth muscle cell controls. Nine +/- 2% (mean +/- SEM; n = 20) of the cells classified as inactive osteoblasts and 69 +/- 3% (n = 19) of the cells identified as active osteoblasts on the bone surface contained alpha-smooth muscle actin. This difference was highly statistically significant (Student's t test, p < 0.0001). Similar profiles of alpha-smooth muscle actin-expressing cells were found in explants cultured for up to 12 weeks. Cells forming a layer on the surface of the explants and growing out from them in monolayer also contained alpha-smooth muscle actin by immunohistochemistry and Western blot analysis. Human osteoblasts can express the gene for alpha-smooth muscle actin. This expression should be considered a phenotypic characteristic of this cell type, conferred by its progenitor cells: bone marrow stromal-derived stem cells, and perhaps pericytes and smooth muscle cells.     

Cortical fibroblast culture from human biopsies.

BACKGROUND: Tubulointerstitial fibrosis is an integral part of progressive renal disease. Human cortical fibroblasts are believed to be key effector cells in fibrogenesis. Thus, a reliable culture of these cells is necessary for studies of their pathophysiology. METHODS: Cortical fibroblast culture from routine kidney biopsies were analyzed and the cells were characterized. Indirect immunofluorescence staining was done after the first passage for cytokeratin, vimentin, alpha-smooth muscle actin, CD 44, CD 54, CD 68, collagen types I, III, and HLA-DR. We then assessed the utility of the putative fibroblast markers CD 90, prolyl-4-hydroxylase (P4H) and F1b in simultaneous stainings of tubular epithelial cells. RESULTS: During the study period, 49 biopsy cores were cultured and cortical fibroblasts could be successfully established in 21 cases (42.9%). There was no relation between the success rate of culture and the degree of interstitial fibrosis, but an association was seen with the time of completion of the first passage. There was a negative correlation between the extent of scarring and the percentage of cytokeratin positive cells (r = -0.66, p < 0.001). All primary fibroblasts were negative for factor VIII, HLA-DR, CD 68, and cytokeratin. They expressed alpha-smooth muscle actin and collagen types I and III to variable degrees. There was a robust correlation between the percentage of alpha-smooth muscle actin positive cells and interstitial scarring but no such association with collagen type I or type III positive cells. The three putative fibroblast markers did not prove useful in differentiating between tubular epithelial cells and fibroblasts. However, since only fibroblasts stained positive for CD 90 and negative for cytokeratin, these two markers may suffice to distinguish fibroblasts from other renal cellular elements. CONCLUSIONS: Cortical renal fibroblasts can be easily cultured from kidney biopsy cores, though the success rate of pure cultures is below 50%. Staining for CD 90 and cytokeratin may suffice for initial characterization of these cells.     

Morphological and Pharmacological Characterization of Guinea-Pig Prostatic Smooth Muscle Cells in Vitro

Background Prostatic smooth muscle is thought to play a major role in the pathogenesis of bladder outlet obstruction in patients with benign prostatic hypertrophy. However, the physiology of prostatic smooth muscle cells remains largely unknown, in part due to the lack of a suitable model system. We therefore sought to establish an in vitro culture of guinea pig prostatic smooth muscle cells. Methods: Immature guinea pig prostate was treated by enzymatic digestion and the cells obtained were used to initiate the primary culture. After 3 to 4 passages, cultured smooth muscle cells were examined morphologically by immunocytochemistry and electron microscopy. The contractile properties of cultured smooth muscle cells were also examined.
Results The cultured prostatic cells demonstrated hill and valley morphology, which is a hallmark of smooth muscle cells in vitro, and stained positively for desmin. In addition, electron microscopic examination of ultrastructural morphology revealed myofilaments. Confluent cultures of prostatic smooth muscle cells showed a clear, dose-dependent contractile response to phenylephrine. Furthermore, contraction of the prostatic smooth muscle cells by 10_-6 mol/L phenylephrine was completely inhibited by pretreatment with 10_-6 mol/L terazosin.
Conclusions An in vitro culture of prostatic smooth muscle cells was established. This culture is likely to provide a powerful tool for elucidating the physiology and pathophysiology of prostatic smooth muscle.     

Potential role of vacuolar H-adenosine triphosphatase in neointimal formation in cultured human saphenous vein

OBJECTIVE: Vacuolar H(+)-adenosine triphosphatase plays a pivotal role in pH regulation and molecular transport across the vacuolar membranes and is involved in cell proliferation and transformation. In the present study, possible involvement of vacuolar H(+)-adenosine triphosphatase in neointimal formation was investigated in an organ culture model of human saphenous vein. Methods and results: Cultured saphenous vein segments developed neointimal formation and marked thickening of the media within 14 days. Neointimal formation and medial thickening were completely inhibited by 10 nmol/L bafilomycin A(1), a selective inhibitor of vacuolar H(+)-adenosine triphosphatase, although structurally related macrolide antibiotics FK-506 and erythromycin were without an effect. The neointimal cells were positive for alpha-smooth muscle actin and vimentin but negative for desmin, indicative of myofibroblasts. The emergence of myofibroblasts was inhibited, and endothelial cells were preserved in the saphenous vein segments treated with bafilomycin A(1). Uptake of bromodeoxyuridine, a proliferation marker, by myofibroblasts was abrogated in the saphenous vein segments treated with 10 nmol/L bafilomycin A(1). Detection of apoptotic cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling concomitant with identification of desmin-expressing smooth muscle cells demonstrated that neointimal myofibroblasts, but not medial smooth muscle cells, that expressed desmin underwent apoptosis by treatment with bafilomycin A(1). CONCLUSIONS: These results suggest that vacuolar H(+)-adenosine triphosphatase may be involved in myofibroblast growth that contributes to neointimal formation and medial thickening in cultured human saphenous vein. Increased sensitivity of myofibroblasts, but not endothelial cells, and differentiated smooth muscle cells to bafilomycin A(1) may have potential therapeutic implications in the treatment for vein graft disease.     

从膀胱癌患者分离并培养人膀胱平滑肌细胞

目的：建立从膀胱癌患者的分离并培养膀胱平滑肌细胞的实验技术.方法：取一小块无明显肿瘤生长的膀胱组织,分离并培养膀胱平滑肌细胞;动态观察细胞形态变化、生长增殖情况以及平滑肌肌动蛋白（SMA）、结蛋白（Desmin）和广谱细胞角蛋白（AE1/AE3）的表达.结果：接种24 h后即有长梭形细胞贴壁生长,10天后长至80%融合,呈典型的＂峰谷＂样形态;传代后1天为潜伏期,2～6天为指数生长期,然后进入融合平台期,需再次传代.第2代细胞的SMA和Desmin表达阳性率分别高达（99.0±0.8）%和（97.0±2.1）%,不表达AE1/AE3.随着传代次数的增加,细胞去分化,细胞形态变成短梭状或椭圆形;SMA和Desmin的表达开始下降,传至第5代时,SMA和Desmin阳性率分别降至（78.0±3.3）%和（74.0±2.6）%;至第7代时,SMA和Desmin阳性率降至（51.0±3.0）%和（49.0±2.6）%.第7代细胞经血清饥饿培养48 h后,细胞又能再分化,形态转变成长梭状,SMA和Desmin阳性率可分别升至（90.0±3.5）%和（88.0±2.5）%,具有显著性差异.结论：本研究所培养的人膀胱平滑肌细胞具有较高的纯度,血清饥饿能促进去分化的细胞再分化,能为构建组织工程膀胱提供种子细胞.     

Subcutaneous tissue fibroblasts transfected with muscle and nonmuscle actins: A good in vitro model to study fibroblastic cell plasticity

Cultured fibroblasts develop several biochemical and morphological properties of smooth muscle cells, particularly the expression of alpha-smooth muscle actin, the actin isoform typical of vascular smooth muscle cells. They resemble modified fibroblasts or myofibroblasts observed in granulation tissue during wound repair and in fibrotic situations. We have analysed by immunolabeling the fate of exogenous epitope-tagged actin isoforms by transfection of the corresponding cDNAs into fibroblasts cultured from rat subcutaneous tissue. Tagged muscle actins were efficiently integrated into stress fibers and did not produce obvious changes in cell shape of transfected cells. Transfected nonmuscle actins in contrast changed the morphology and were not or poorly incorporated into stress fibers. These cultured subcutaneous fibroblasts behave similarly to smooth muscle cells when transfected with the same actin encoding cDNAs, indicating another common characteristic of these two cell types in sorting and targeting actin isoforms. Subcutaneous fibroblasts transfected with muscle and nonmuscle actin isoforms provide a good in vitro model to analyze the intracellular sorting of isoactins and to improve our knowledge of myofibroblast characterization and differentiation during tissue repair as well as to understand the relationships between modifications of actin cytoskeleton, adhesion and extracellular matrix proteins.     

Human neural crest stem cells transplanted in rat penile corpus cavernosum to repair erectile dysfunction

OBJECTIVE

To investigate the feasibility of applying neural crest stem cells (NCSCs), with multipotent capacity, to repair injury in the penile cavernosum, the HNC10.K10 (K10) immortalized NCSC line was transplanted into the penile cavernosum of adult rats, as one of the causes of erectile dysfunction is damaged penile cavernous smooth muscle cells and sinus endothelial cells.

MATERIALS AND METHODS

The K10 human NCSC line was generated via transfection of primary cultured NCSC with a retroviral vector encoding v‐myc. K10 NCSCs were transplanted into the cavernosum of adult rats. The expression of cell type‐specific markers for endothelial cells (CD31 and von Willebrand factor), and specific markers for smooth muscle cells (smooth muscle cell actin, calponin, and desmin) was determined immunohistochemically in the penile cavernosum of rats 2 weeks after transplantation.

RESULTS

In the rat cavernosum, transplanted K10 NCSCs identified by human nuclear antigen labelling expressed cell type‐specific markers for endothelial cells (CD31 and von Willebrand factor), and specific markers for smooth muscle cells (smooth muscle cell actin, calponin, and desmin) 2 weeks after transplantation. Human NCSCs transplanted into the rat penile corpus cavernosum differentiated into endothelial cells or smooth muscle cells, as shown by their expression of cell type‐specific markers for the cell types.

CONCLUSION

It appears that NCSCs are an ideal cell source for reconstructing endothelial and smooth muscle cells in the corpus cavernosum in cell therapy for patients with erectile dysfunction.     

降钙素基因相关肽对糖尿病性ED大鼠阴茎海绵体平滑肌细胞表型转化的影响

目的:了解降钙素基因相关肽(CGRP)对糖尿病性ED大鼠阴茎海绵体平滑肌细胞表型转化的影响。方法:利用链脲佐菌素建立糖尿病及糖尿病性ED大鼠模型。阴茎海绵体平滑肌细胞原代培养,并进行免疫细胞化学染色鉴定。实验分为2组:正常对照组和糖尿病性ED大鼠组。不同浓度(0、10,60,100 nmol/L)CGRP作用24h后,利用qRT-PCR检测各组细胞碱性调宁蛋白和骨桥蛋白mRNA的表达。结果:各组原代培养阴茎海绵体平滑肌细胞α-肌动蛋白阳性细胞率为(95.94±0.03)%。与正常对照组比较,糖尿病组ED大鼠阴茎海绵体平滑肌细胞碱性调宁蛋白mRNA表达显著减少(4.41±0.29 vs 10.35±0.62,P<0.01),而骨桥蛋白mRNA表达水平显著上调(5.28±0.32 vs 1.32±0.24,P<0.01)。当CGRP作用的终浓度为100 nmol/L时,糖尿病组大鼠阴茎海绵体平滑肌细胞经CGRP作用后,与未经其作用相比,碱性调宁蛋白mRNA表达显著上调(6.90±0.22 vs 4.41±0.29,P<0.01),而骨桥蛋白mRNA表达水平显著减少(3.26±0.31 vs 5.28±0.32,P<0.01)。结论:CGRP可使糖尿病性ED大鼠阴茎海绵体平滑肌细胞表型从合成型向收缩型转化。     

Obstruction of St Jude Medical valves in the aortic position: histology and immunohistochemistry of pannus

OBJECTIVE: This study aims to reveal the morphological, histological, and immunohistochemical mechanism of pannus formation using resected pannus tissue from patients with prosthetic valve dysfunction. METHOD: Eleven patients with prosthetic valve (St Jude Medical valve) dysfunction in the aortic position who underwent reoperation were studied. We used specimens of resected pannus for histological staining (hematoxylin and eosin, Grocott's, azan, elastica van Gieson) and immunohistochemical staining (transforming growth factor-beta, transforming growth factor-beta receptor 1, alpha-smooth muscle actin, desmin, epithelial membrane antigen, CD34, factor VIII, CD68KP1, matrix metalloproteinase-1, matrix metalloproteinase-3, and matrix metalloproteinase-9). RESULTS: Pannus without thrombus was observed at the periannulus of the left ventricular septal side; it extended into the pivot guard, interfering with the movement of the straight edge of the leaflet. The histological staining demonstrated that the specimens were mainly constituted with collagen and elastic fibrous tissue accompanied by endothelial cells, chronic inflammatory cells infiltration, and myofibroblasts. The immunohistochemical findings showed significant expression of transforming growth factor-beta, transforming growth factor-beta receptor 1, CD34, and factor VIII in the endothelial cells of the lumen layer; strong transforming growth factor-beta receptor 1, alpha-smooth muscle actin, desmin, and epithelial membrane antigen in the myofibroblasts of the media layer; and transforming growth factor-beta, transforming growth factor-beta receptor 1, and CD68KP1 in macrophages of the stump lesion. CONCLUSIONS: Pannus appeared to originate in the neointima in the periannulus of the left ventricular septum. The structure of the pannus consisted of myofibroblasts and an extracellular matrix such as collagen fiber. The pannus formation after prosthetic valve replacement may be associated with a process of periannular tissue healing via the expression of transforming growth factor-beta.     

Growth of bone marrow stromal cells on small intestinal submucosa: an alternative cell source for tissue engineered bladder

OBJECTIVE: To assess the potential use of bone marrow stromal cell (BMSC)-seeded biodegradable scaffold for bladder regeneration in a canine model, by characterizing BMSCs and comparing them to bladder smooth muscle cells (SMCs) by immunohistochemistry, growth capability, and contractility. MATERIALS AND METHODS: Bone marrow was taken by direct needle aspiration from the femurs of five beagle dogs for the in vitro study. Mononuclear cells were isolated by Ficoll-Paque density gradient centrifugation and cultivated in medium 199 with 10% fetal bovine serum. BMSCs were characterized by cell proliferation, in vitro contractility, immunohistochemical analysis, and the growth pattern on small intestinal submucosa (SIS) scaffolds compared to bladder SMC cultures from the same dogs. Another six dogs had a hemicystectomy and bladder augmentation with BMSC-seeded (two), bladder cells including urothelial cells plus SMC-seeded SIS (two) and unseeded SIS scaffolds (two). The six dogs were followed for 10 weeks after augmentation. RESULTS: In vitro BMSCs had a significant contractile response to calcium-ionophore, with a mean (sem) 36 (2)%, relative contraction (P < 0.01), which was similar to bladder SMCs but markedly different from fibroblasts. BMSCs also expressed alpha-smooth muscle actin by immunohistochemical staining and Western blotting, but did not express desmin or myosin. In vivo, both BMSC-seeded and bladder cell-seeded SIS grafts had solid smooth-muscle bundle formation throughout the graft. CONCLUSIONS: BMSCs had a similar cell proliferation, histological appearance and contractile phenotype as primary cultured bladder SMCs. SIS supported three-dimensional growth of BMSCs in vitro, and BMSC-seeded SIS scaffold promoted bladder regeneration in a canine model. BMSCs may serve as an alternative cell source in urological tissue engineering.