Buckwalter J A, Pedrini-Mille A, Pedrini V, Tudisco C
J Bone Joint Surg Am. 1985 Feb;67(2):284-94.
The ground substance of the intervertebral disc consists primarily of proteoglycans, which give the tissue its stiffness to compression and its resiliency. To investigate the structure and composition of these molecules, we extracted them from human infant nucleus pulposus under associative conditions and from human infant annulus fibrosus and cartilage end-plate under dissociative conditions. We examined the degree of aggregation, the composition, the electron microscopic appearance, and the dimensions of the proteoglycans of the intervertebral disc and compared their structure and dimensions with those of the proteoglycans from bovine hyaline cartilage. Aggregates represented 52 per cent of the proteoglycans of the nucleus pulposus between the ages of one and ten days but only 28 per cent between the ages of six and eight months. Preparations from the corresponding annuli contained 59 per cent aggregates at one to ten days and 47 per cent at six months. The corresponding cartilage end-plate preparations contained 45 and 40 per cent aggregates. The proteoglycans of the annulus fibrosus and cartilage end-plate contained more protein and less hexosamine than did those of the nucleus pulposus. Electron microscopy showed that approximately two-thirds of the aggregates from nucleus pulposus consisted of very short hyaluronate filaments with closely packed monomers. The other third had longer hyaluronate filaments and wider distances between monomers, and closely resembled the aggregates from the annulus fibrosus and cartilage end-plate. Aggregated monomers consisted of two segments: a thin segment connecting directly to the hyaluronic acid filament and a thick segment extending peripherally from the thin segment. The thin segment formed about 12 per cent of the total monomer length in the samples from all three disc tissues. The lower proportion of aggregated monomers, the lower protein content, and the smaller aggregates with closely packed monomers suggest that the nucleus pulposus may contain less link protein than do the annulus fibrosus and cartilage end-plate. Compared with proteoglycan aggregates from bovine hyaline cartilage, proteoglycan aggregates from human intervertebral disc were shorter and had fewer monomers and wider spacing between monomers. The aggregated monomers from the three components of the intervertebral disc had an average length of 209 +/- 90 nanometers, compared with 210 +/- 114 nanometers for monomers from hyaline cartilage of skeletally mature cows, 250 +/- 116 nanometers for monomers from hyaline cartilage of skeletally immature calves, and 288 +/- 108 nanometers for monomers from fetal animals.(ABSTRACT TRUNCATED AT 400 WORDS)
椎间盘的细胞外基质主要由蛋白聚糖组成，这些蛋白聚糖赋予组织抗压的刚度和弹性。为了研究这些分子的结构和组成，我们在缔合条件下从人类婴儿髓核中提取蛋白聚糖，并在解离条件下从人类婴儿纤维环和软骨终板中提取。我们检查了椎间盘蛋白聚糖的聚集程度、组成、电子显微镜外观和尺寸，并将它们的结构和尺寸与来自牛透明软骨的蛋白聚糖进行比较。在1至10日龄的髓核中，聚集体占蛋白聚糖的52%，但在6至8月龄时仅占28%。相应纤维环在1至10日龄时的制剂中聚集体含量为59%，在6月龄时为47%。相应的软骨终板制剂中聚集体含量分别为45%和40%。纤维环和软骨终板的蛋白聚糖比髓核的蛋白聚糖含有更多的蛋白质和更少的己糖胺。电子显微镜显示，髓核中约三分之二的聚集体由非常短的透明质酸细丝和紧密堆积的单体组成。另外三分之一具有更长的透明质酸细丝和单体之间更宽的间距，并且与纤维环和软骨终板的聚集体非常相似。聚集的单体由两个部分组成：一个直接连接到透明质酸细丝的细段和一个从细段向周边延伸的粗段。在来自所有三种椎间盘组织的样本中，细段约占单体总长度的12%。聚集单体的比例较低、蛋白质含量较低以及单体紧密堆积的聚集体较小，这表明髓核中的连接蛋白可能比纤维环和软骨终板中的少。与来自牛透明软骨的蛋白聚糖聚集体相比，来自人类椎间盘的蛋白聚糖聚集体更短，单体更少，单体之间的间距更宽。椎间盘三个组成部分的聚集单体平均长度为209±90纳米，而骨骼成熟奶牛透明软骨单体的平均长度为210±114纳米，骨骼未成熟小牛透明软骨单体的平均长度为250±116纳米，胎儿动物单体的平均长度为288±108纳米。（摘要截断于400字）
