大鼠颈椎间盘老化及退变过程中髓核形态变化规律的实验研究

目的：研究颈椎间盘自然老化及退变过程中髓核软骨样细胞的来源和脊索性髓核向纤维软骨性髓核转化的规律及其与颈椎间盘退变的关系。方法：4周龄SD大鼠76只，随机分成两组。实验组40只大鼠通过截除前肢制备双后肢大鼠颈椎间盘退变的动物模型，按术后3、6、9、12个月4个时间段分组，每组10只；对照组36只大鼠未予处置，按实验开始后4、8、12、16个月分4组，每组9只。制备C4-5，C5-6和C6-7椎间盘中矢状面组织学切片，行HE、番红-O染色，研究观察不同老化及退变程度颈椎间盘髓核中软骨样细胞的起源和脊索性髓核向纤维软骨性髓核转化的规律。结果：随着颈椎间盘的不断老化，终板的软骨细胞向髓核迁移，脊索性髓核向心性皱缩并最终完全被纤维软骨性髓核取代，在此过程中，软骨终板的厚度逐渐变薄，进而出现缺损或断裂；在颈椎间盘退变的过程中，这一转化完成的更快、更早。结论：髓核中的软骨样细胞由终板的软骨细胞迁移而来，通过向心性的产生和沉积胶原纤维，脊索性髓核逐渐被纤维软骨性髓核替代，这一过程既是颈椎间盘成熟和老化的自然环节也可能是颈椎间盘退变的启动环节。     

尼古丁在人椎间盘髓核细胞退变中的作用

目的探讨不同浓度及时间的尼古丁在人椎间盘髓核细胞退变中的作用。方法随机选择5例腰椎骨折患者的椎间盘髓核组织进行体外细胞培养,种于12孔板中,按照0、1、33.3、100、200、500ng/m L的尼古丁浓度以及1、2、3、7、10天加入来培养,每组细胞用Trizol法提取总RNA,用荧光定量PCR测定AQP1,AQP3和II型胶原(Collagen)以及蛋白多糖(Aggrecan)的m RNA表达。用SPSS19.0进行统计分析。结果随着尼古丁浓度升高及培养时间的延长,髓核细胞形态变化明显,贴壁能力减弱,胞质减少,胞核萎缩,空泡形成,凋亡增加。且细胞AQP1及AQP3的m RNA水平随着尼古丁浓度及时间的增加而降低,II型胶原及蛋白聚糖m RNA水平也降低,细胞发生退变。结论尼古丁会降低人椎间盘髓核细胞AQP1和AQP3的表达,进而降低髓核细胞II型胶原和蛋白聚糖的表达,促进椎间盘退变,且作用时间越长,浓度越高,细胞退变越严重。     

多次胶原酶消化法培养小鼠椎间盘髓核细胞

背景：椎间盘为无血运组织,椎间盘髓核细胞为分化终末细胞,细胞增殖能力较差,体外培养难度较大。 目的：探索小鼠椎间盘髓核细胞体外分离培养的方法。 方法：取小鼠椎间盘髓核组织,使用多次胶原酶消化的方法,分离培养髓核组织细胞,接种,传代,取第2代细胞,分别采用免疫细胞化学和RT-PCR方法检测椎间盘髓核细胞特征性分泌物Ⅱ型胶原和聚合蛋白的分泌量及mRNA的表达,并与软骨细胞,成骨细胞及成纤维细胞进行比较。 结果与结论：椎间盘髓核细胞贴壁后呈现软骨细胞的形态;Ⅱ型胶原和聚合蛋白染色均为阳性;Ⅱ型胶原和聚合蛋白mRNA表达与软骨细胞相同,与成纤维细胞和成骨细胞存在明显差别。说明多次胶原酶消化的方法可以获得大量纯净的椎间盘髓核细胞,性状稳定。     

苦参碱对椎间盘退变大鼠髓核细胞凋亡的影响

背景:髓核细胞凋亡是引发椎间盘退变的主要病理基础,炎症和过氧化反应是导致髓核细胞凋亡的重要因素。研究表明苦参碱具有抗氧化、衰老、炎症和细胞凋亡等作用,可作为治疗椎间盘退变的潜在药物。目的:观察苦参碱调节环状GMP-AMP合成酶-干扰素基因刺激因子(cGAS-STING)信号通路对椎间盘退变大鼠髓核细胞凋亡的影响。方法:①将处于对数生长期的大鼠髓核细胞分6组处理:除对照组外,模型组、苦参碱低剂量组、苦参碱高剂量组、空载组、苦参碱高剂量+cGAS过表达组采用氧糖剥夺建立椎间盘退变细胞模型,造模同时苦参碱低剂量组、苦参碱高剂量组分别给予0.4,0.8 mmol/L苦参碱处理,空载组转染空载质粒,苦参碱高剂量+cGAS过表达组给予0.8 mmol/L苦参碱处理并转染cGAS过表达质粒。处理24 h后,检测细胞活性与凋亡,细胞内活性氧、超氧化物歧化酶、肿瘤坏死因子α及白细胞介素1β水平,以及细胞内凋亡蛋白、cGAS-STING通路蛋白表达。②将60只SD大鼠随机分为6组,每组10只:除对照组外,模型组、苦参碱低剂量组、苦参碱高剂量组、空载组、苦参碱高剂量+cGAS过表达组建立椎间盘退变模型;造模12周后,苦参碱低剂量组、苦参碱高剂量组分别灌胃给予60,120 mg/kg苦参碱(1次/d),空载组尾静脉注射空载质粒(2次/周),苦参碱高剂量+cGAS过表达组灌胃给予120 mg/kg苦参碱+尾静脉注射cGAS过表达质粒,连续治疗3周。给药结束后取材,检测细胞凋亡,活性氧、超氧化物歧化酶、肿瘤坏死因子α及白细胞介素1β水平,以及凋亡蛋白、cGAS-STING通路蛋白表达。结果与结论:①与对照组比较,模型组细胞活性、超氧化物歧化酶水平降低(P<0.05),细胞凋亡率、活性氧含量、肿瘤坏死因子α和白细胞介素1β水平及cGAS、STING、cleaved caspase-3和Bax蛋白表达升高(P<0.05);苦参碱可呈剂量依赖性地改善上述因细胞造模造成的各指标变化(P<0.05),而cGAS过表达可部分拮抗高剂量苦参碱的改善作用。②在动物实验中获得了与体外细胞实验类似的结果。③结果表明,苦参碱可通过阻断cGAS-STING信号传导抑制炎症和氧化应激反应,进而减轻椎间盘退变大鼠髓核细胞凋亡、提升其活性。     

磁共振动态增强参数对女性乳腺病变的诊断意义

目的:探究MRI动态增强参数对女性乳腺疾病鉴别诊断价值.方法:收集本院2019年2月至2021年10月收治的101例乳腺疾病患者的资料.以病理检查结果为"金标准",对比良、恶性乳腺病变的MRI动态增强参数值,分析MRI动态增强诊断乳腺疾病的准确性、敏感性和特异性.结果:101例乳腺病变患者中良性病灶69例(68.32％...     

幼年与成年兔椎间盘髓核细胞的形态学差异及其意义

目的探讨幼年与成年兔髓核细胞的形态学差异。方法利用激光共聚焦显微镜和透射电镜,对幼年和成年兔的髓核组织进行组织细胞水平和超微结构的观察。结果幼年兔的髓核细胞呈圆形,簇状分布,其直径为(266±167)μm,细胞簇的密度为每个高倍(×40)视野(14.9±4.3)个,细胞内含有大量空泡状的包含体。成年兔的髓核细胞呈圆形或类圆形,细胞簇小或呈单个散在分布,细胞簇的直径为(94±42)μm,细胞簇密度为每个高倍(×40)视野(8.0±2.4)个细胞,其中包含体数目少且不含大的包含体。结论幼年与成年兔的髓核细胞具有明显的形态结构差异。椎间盘成年期发生的这种形态结构上的变化可能是随年龄增加而椎间盘生物学功能逐渐降低的原因之一。     

纤维环穿刺法与髓核抽吸法建立兔椎间盘退变模型的比较

目的:比较采用纤维环穿刺法和髓核抽吸法建立兔椎间盘退变动物模型的不同。方法:新西兰大白兔经腹膜外入路暴露腰3/4、腰4/5、腰5/6椎间隙,纤维环穿刺组采取针刺纤维环,髓核抽吸组抽吸髓核8周后核磁共振观察椎间盘变化,生化分析椎间盘中蛋白多糖含量,免疫组织化学检测Ⅱ型胶原表达。结果:术后8周与对照组相比,采用两种方法的椎间隙高度与T2信号手术前后变化比值,以及Ⅱ型胶原和蛋白多糖含量,差异显著。其中髓核抽吸组的Ⅱ型胶原和蛋白多糖含量明显低于纤维环穿刺组。结论:髓核抽吸法建立兔退变椎间盘模型退变程度大于纤维环穿刺法。     

人工椎间盘及髓核假体的生物力学

背景：全椎间盘或髓核假体是否符合人的椎间盘的解剖特点、生物力学是目前关注的焦点。 目的：综述目前存在的人工椎间盘及髓核假体的类型及其生物力学特征。 方法：由第一作者用计算机检索万方数据库、中国期刊全文数据库和PubMed数据库,检索时间：1989/2011,检索词分别为“椎间盘、髓核、人工假体、生物力学”和“intervertebral diac,nucleus pulposus,artificial prosthesis,biomechanics”,语言分别设定为中文和英文。纳入与人工椎间盘及髓核假体的材料类型及其生物力学特性相关的研究,排除重复性研究。共检索到72篇文章,按纳入和排除标准对文献进行筛选,共纳入26篇文章进行分析。 结果与结论：目前应用于人工椎间盘的材料有钴铬合金、钛合金、不锈钢、陶瓷和超高分子量聚乙烯等。应用不同材料制备的人工椎间盘假体校多,其中Bryan假体在临床中最常用,体外实验、三维有限元分析及临床研究均证实其具有良好的生物力学特性,置换成功率高。目前存在的人工髓核假体有预制型和原位聚合型,由于其手术损伤小,是目前研究的热点,但仍很难达到人体髓核的生物力学功能。发掘新型材料和设计个性化假体是将来的发展方向。      

基质金属蛋白酶1在不同程度退变腰椎间盘髓核与纤维环中的表达及意义

背景：基质金属蛋白酶在椎间盘退变中通过影响基质合成及降解导致基质成分紊乱及功能的改变。 目的：观察基质金属蛋白酶1在人类退变腰椎间盘组织中的表达变化。 方法：获取经手术治疗腰椎间盘突出症患者椎间盘标本30份,突出型、脱出型、游离型各10份,分离髓核与纤维环,设为实验组;腰椎损伤致椎体骨折切除椎间盘10份设为对照组。应用免疫组织化学法检测基质金属蛋白酶1在椎间盘中髓核与纤维环细胞中的表达。 结果与结论：①苏木精-伊红染色显示,对照组椎间盘标本纤维环仍保持着致密的板层结构,实验组椎间盘组织多呈纤维化样改变。②两组髓核细胞中基质金属蛋白酶1表达均高于纤维环细胞中的表达。③实验组突出型椎间盘标本中基质金属蛋白酶1表达明显高于对照组(P < 0.01),脱出型和游离型椎间盘标本中基质金属蛋白酶1表达明显高于突出型 (P < 0.01)。 关键词：椎间盘退变;基质金属蛋白酶1;椎间盘突出症;髓核;纤维环 doi:10.3969/j.issn.1673-8225.2012.13.015     

Ultrastructure of the human intervertebral disc: II. Cells of the nucleus pulposus

The cells of the intervertebral disc exist in a unique environment; not only are discs subject to large mechanical loads, they are the largest avascular structures in the body. To describe the ultrastructure and age changes in cells from human nucleus pulposus, we studied these cells in individuals ranging in age from the 26th week of fetal life to 91 years. Viable chondrocyte-like cells existed in specimens from all ages. The presence of Golgi cisternae and well-developed endoplasmic reticulum in these cells suggests that they are capable of producing and maintaining the extracellular matrix. Necrotic cells were also present in all samples, and many cells which appeared viable when examined by light microscopy proved to be necrotic when examined by electron microscopy. The percentage of necrotic cells increased with age from 2% or less in fetal specimens to over 50% in adults. In addition, with age, a distinct pericellular matrix or “nest,” consisting of collagen fibrils, fine filaments, dense particles, and banded structures, formed around most cells with no apparent preference for viable or necrotic cells. Nest formation and increasing density of the cell nests may reflect accumulation of cell products.     

椎间盘微环境下椎间盘源性干细胞和髓核间充质干细胞的活性

文题释义：椎间盘微环境：在正常情况下,髓核组织缺乏血液供应,其营养代谢主要依赖渗透。由于代谢产物等影响,椎间盘组织内部的pH值为6.9-7.2,被认为是人体内最恶劣的环境之一,在这种条件下细胞正常代谢能力受到很大抑制,即使是特化的髓核细胞其代谢率也仅为正常的32%。当椎间盘退变后,葡萄糖及氧浓度进一步下降,乳酸堆积,pH值降低和代谢产物进行性增加。 髓核间充质干细胞：经过前期实验发现髓核间充质干细胞经自体移植于椎间盘局部,可以分化为纤维环细胞和髓核细胞,或者通过旁分泌细胞因子来促进组织细胞的再生,但髓核间充质干细胞在椎间盘微环境中存活量级并不清楚。椎间盘源性干细胞和髓核间充质干细胞在椎间盘微环境下的生存变化差异性也还是未知。 背景：椎间盘微环境对干细胞生物学行为具有重要作用,拟通过微环境调节作用来实现不依赖种子细胞的椎间盘组织修复。 目的：探讨椎间盘微环境下椎间盘源性干细胞和髓核间充质干细胞活性的差异。 方法：健康雄性SD大鼠10只,按照解剖区分离椎间盘骨组织,用Ⅱ型胶原酶消化后进行体外培养椎间盘源性干细胞;分离髓核组织,采用酶消化法体外培养髓核间充质干细胞。将获得的椎间盘源性干细胞和髓核间充质干细胞在体外进行正常条件、椎间盘微环境条件下培养扩增,培养第1-6天采用MTT法测定细胞增殖情况,培养第1,3,6天采用流式细胞技术检测CD29阳性表达水平。 结果与结论：①在不同环境的培养条件下,椎间盘源性干细胞和髓核间充质干细胞增殖情况呈相反趋势。在正常培养条件下,椎间盘源性干细胞和髓核间充质干细胞呈增殖状态,第4-6天为对数增殖期,两者差异无显著性意义(P > 0.05);在椎间盘微环境条件下,髓核间充质干细胞的增殖活性明显低于椎间盘源性干细胞,差异有显著性意义(P < 0.05);②在椎间盘微环境条件下培养第3,6天,椎间盘源性干细胞表面CD29阳性抗原表达水平明显高于髓核间充质干细胞,差异有显著性意义(P < 0.05);③结果表明,在椎间盘微环境条件下,髓核间充质干细胞和椎间盘源性干细胞活性受到一定程度的抑制,但椎间盘源性干细胞较髓核间充质干细胞保留更多的细胞活性。 ORCID: 0000-0002-3582-5630(胡炜) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Identification of cell markers of the nucleus and annulus of bovine intervertebral discs

Introduction The intervertebral disc consists of three regions, the nucleus pulpous and the inner and outer annulus containing cells with individual phenotypes. However, no molecular markers are known to discriminate between the various cell types. Molecular markers would help identify the cell types through development of the disc, ageing of the disc, cell localization and in pathological states such as degenerative disc disease and scoliosis. Here, we present data revealing major difference between the cell types using SDS‐PAGE and mass spectrometry. Such differences will help to develop molecular markers to identify the cell types using immunoblotting and immunohistochemistry. Methods Intervertebral discs were isolated from bovine tails and separated into three distinct regions of the nucleus, inner and outer annulus. The isolated regions were separately digested with collagenase and peptidase overnight. The remaining cell suspensions were sieved through a filter to remove large particles and then extensively washed. The cells were then separated into membrane and supernatant fractions by incubation with Triton followed by centrifugation. SDS‐PAGE analysis using a variety of acylamide gels of the various fractions revealed bands of interest that where then cut from the gel, digested with trypsin and analysed by mass spectrometry. The peptide mass/charge data were collected and then compared with a databank of known peptide masses to give a composite protein mass. Results Analysis of the membrane and supernatant fractions of the cells from the three distinct regions in the disc by SDS‐PAGE revealed unique protein patterns between the regions and fractions. A large broad band from the membrane of nucleus cells was analysed by mass spectrometry that revealed strong matches for myosin and clathrin and a match for basement membrane collagen‐IV. A control band from the outer annulus also revealed a strong match for myosin and to a lesser extent basement membrane collagen type‐IV. A strong SDS‐PAGE band from the membrane fraction of the outer annulus revealed a mass spectrometry match to actin. Analysis of the corresponding supernatant fraction revealed a strong match to actin, whereas a band of similar molecular weight from the inner annulus revealed another myosin chain. Conclusion The differences revealed in the protein profile of cells from the three regions of disc and the identification of prominent proteins demonstrate that these differences can be used to identify molecular markers. SDS‐PAGE and mass spectrometry analysis of significant bands showed strong matches in the membrane fraction for myosin and clathrin, and also basement membrane collagen‐IV. By using immunoblotting and immunohistochemistry, it will be possible to follow the development, ageing and pathology of the three cell types and will hopefully be extended to finding markers that characterize the individual stages of the degenerative changes. This study will also include genechip technology to identify at the RNA level the difference between the three cell types. This work was funded by the EU EURODISC project (QLK6‐CT‐2002–02582).     

兔腰椎间盘髓核穿刺抽吸后的影像及组织病理学变化

背景：髓核摘除后椎间盘会随时间出现什么样的影像学及组织病理学变化,目前尚不明确。 目的：观察兔腰椎间盘髓核穿刺抽吸术后影像学及组织病理学的变化。 方法：32只日本大耳白兔,用21号针头行L _3/4椎间盘后外侧穿刺抽吸出部分髓核组织,L _2/3椎间盘作为正常对照椎间盘,于抽吸后2,4,8,12周时按照分组取8只兔子行腰椎侧位X射线检查,测量L _3/4 、L _2/3椎间隙高度并计算椎间盘高度指数,行正中矢状位MRI检查及椎间盘组织病理学检查。 结果与结论：髓核抽吸后2,4,8,12周椎间盘高度呈逐渐降低趋势,但8-12周变化减小,与正常对照组椎间盘相比,各时间点椎间盘高度指数显著降低(P < 0.05)。抽吸后2,4,8,12周的髓核信号强度随时间逐渐降低,8周时已达改良Thompson分级标准的4级。抽吸后凝胶状髓核组织随时间逐渐出现裂隙,形态逐渐紊乱,12周时呈现明显的纤维化表现,髓核4周时出现较多的类软骨细胞,呈现活跃状态,髓核细胞明显减少,抽吸后8,12周髓核内纤维样细胞增多,类软骨细胞数量减少,纤维环随时间逐渐出现扭曲,排列紊乱,突起,出现分层、纤维断裂现象。说明后外侧纤维环穿刺髓核抽吸后,兔腰椎间盘X射线高度、MRI T2加权信号强度随时间逐渐降低、减弱,椎间盘组织逐渐出现退变病理改变,但8-12周其变化趋于缓和。中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程全文链接：     

细胞移植及髓核组织工程重建修复椎间盘退变

背景：通过细胞组织工程将细胞或细胞支架复合体植入退变缺损的椎间盘内,使退变的椎间盘再生可能是治疗椎间盘退变性疾病最为理想的方法。 目的：评价组织工程髓核体内移植抑制腰椎间盘退变的临床疗效及应用前景。 方法：由第一作者检索1990/2010 PubMed数据、中国知网及万方数据库有关组织工程髓核、组织工程材料及骨髓间充质干细胞治疗腰椎间盘退变方面的文献。 结果与结论：目前常用的细胞支架主要包括胶原支架、琼脂糖支架、藻酸盐支架、聚乙醇酸支架与壳聚糖支架以及复合材料等。通过自体椎间盘细胞或间充质干细胞结合基因技术筛选种子细胞,进行细胞和/或细胞支架复合体移植恢复或再生相关细胞外基质的合成,通过逆转和修复椎间盘细胞病理性改变,为退变的椎间盘组织和功能恢复提供了全新的治疗策略。     

Quantitative analysis of diurnal variation in volume and water content of lumbar intervertebral discs

The Cavalieri method of modern design stereology has been used in combination with magnetic resonance imaging (MRI) to obtain unbiased estimates of the volume of the lumbar intervertebral discs immediately at the end of a day of normal activity and again following a night's rest. In addition, pixel-by-pixel mapping of the T2-relaxation time has been used to characterize objectively the tissues of the intervertebral discs. The mean increase in height of seven female subjects of average age 21 years (range 19–23 years) measured with a stediometer was 19.3 mm (range 8–26 mm). Image analysis showed that the mean overnight increase in volume of lumbar discs was 1300 mm³ (range 100–2700 mm³). The increase in volume of the disc was accompanied by an increase in the T2-relaxation time of the nucleus pulposus. This suggests that the change in disc volume is most probably caused by a preferential increase in the water content of the nucleus pulposus. Clin. Anat. 11:1–8, 1998. © 1998 Wiley-Liss, Inc.     

人椎间盘髓核细胞增殖活性与益肾活血通络方的干预调控

背景:NF-κB信号通路与椎间盘退变的关系是骨科学术界研究热点,深入研究椎间盘中各种信号通路的作用,有助于了解椎间盘退变的发生机制。目的:通过研究不同静水压压力下益肾活血通络方含药血清对人椎间盘髓核细胞NF-κB信号通路的调控作用,以期能从分子生物学角度探讨益肾活血通络方治疗椎间盘退变性疾病的可能机制及作用靶点。方法:将第3代人椎间盘髓核细胞分为8组,分别加入益肾活血通络方含药血清,在体外不同静水压加载条件(0.3,1,3 MPa)下作用2,4,6 h后,使用倒置相差显微镜观察椎间盘髓核细胞的形态及生长状况;使用透射电镜观察椎间盘髓核细胞的超微结构;采用CCK-8法检测各组髓核细胞的增殖活性;采用Annexin V-FITC/Propidium Iodide凋亡试剂盒检测髓核细胞的凋亡率;采用Western blot法检测髓核细胞内NF-κB p65、CollagenⅡ、ADAMTS-4、MMP-13、Caspase-3的表达。结果与结论:①在同一压力及作用时间下压力+中药血清组髓核细胞形态较常压组、单纯压力组更完整,生长状况更好,其中0.3,1 MPa压力+中药血清组优于3 MPa压力+中药血清组;②压力+中药血清组髓核细胞增殖活性更高,其中0.3 MPa压力+中药血清组与0.3 MPa单纯压力组比较差异有显著性意义(P<0.05);③压力+中药血清组椎间盘髓核细胞的凋亡率较常压组、单纯压力干预组低(P<0.05);④与单纯压力组比较,压力+中药血清组CollagenⅡ、Caspase-3表达增加,NF-κB p65、ADAMTS-4、MMP-13表达减少(P<0.05);⑤结果表明,益肾活血通络方能增加细胞活性,减少细胞凋亡,有效延缓髓核细胞的退变,其机制可能与椎间盘髓核细胞NF-κB信号通路促进CollagenⅡ、Caspase-3表达,抑制NF-κB p65、ADAMTS-4、MMP-13表达有关。     

Avian intervertebral disc arises from rostral sclerotome and lacks a nucleus pulposus: implications for evolution of the vertebrate disc

Deterioration of the intervertebral discs is an unfortunate consequence of aging. The intervertebral disc in mammals is composed of three parts: a jelly-like center called the nucleus pulposus, the cartilaginous annulus fibrosus, and anterior and posterior endplates that attach the discs to vertebrae. To understand the origin of the disc, we have investigated the intervertebral region of chickens. Surprisingly, our comparison of mouse and chicken discs revealed that chicken discs lack nuclei pulposi. In addition, the notochord, which in mice forms nuclei pulposi, was found to persist as a rod-like structure and express Shh throughout chicken embryogenesis. Our fate mapping data indicate that cells originating from the rostral half of each somite are responsible for forming the avian disc while cells in the caudal region of each somite form vertebrae. A histological analysis of mammalian and nonmammalian organisms suggests that nuclei pulposi are only present in mammals.     

The three-dimensional architecture of the notochordal nucleus pulposus: novel observations on cell structures in the canine intervertebral disc

Cells from the nucleus pulposus of young (< 2 years) and old (> 5 years) non‐chondrodystrophoid dogs were studied using routine histology, confocal laser scanning microscopy and transmission electron microscopy. The architecture of cell structures – from the tissue scale down to subcellular scale – was reported. Clusters of notochordal cells were observed in young nuclei pulposi, ranging from 10 to 426 cells each. These clusters resisted mechanical disruption and showed evidence of cell–cell signalling via gap junctions. Cells (30–40 µm in diameter) within the clusters had a physaliferous appearance, containing numerous large inclusions which ranged from 1 to 20 µm in diameter. The inclusions were surrounded by a dense actin cortex but were not contained by a lipid bilayer. The contents of the inclusions were determined not to be predominantly carbohydrate or neutral lipid as assessed by histochemical staining, but the exact composition of the contents remained uncertain. There were striking differences in the cell architecture of young vs. old nuclei pulposi, with a loss of both cell clusters and physaliferous cells during ageing. These observations demonstrate unique cell structures, which may influence our understanding of the differences between notochordal and chondrocytic cells in the nucleus pulposus. Such differences could have substantial impact upon how we think about development, degeneration and repair of the intervertebral disc.