Nutrient supply and intervertebral disc metabolism
Nutrient supply and intervertebral disc metabolism
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DOI：
10.2106/jbjs.e.01290
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发表时间：
2006-01-01
影响因子：
5.3
通讯作者：
Urban, JPG
中科院分区：
文献类型：
--
作者：
Grunhagen, T;Wilde, G;Urban, JPG
椎间盘细胞的代谢环境由组织的无血管性质决定。由于细胞能量代谢主要通过糖酵解发生，椎间盘细胞需要葡萄糖才能生存，并以高速率产生乳酸。氧气也是细胞活动所必需的，尽管不是生存所必需的;其利用途径尚不清楚。由于组织是无血管的，椎间盘细胞依赖于椎间盘边缘的血液供应来获得营养。椎间盘的髓核和内环由毛细血管供应，毛细血管起源于椎体，穿透软骨下骨，终止于骨-椎间盘交界处。小分子如葡萄糖和氧然后通过在梯度下的扩散到达细胞，所述梯度由通过组织到细胞的运输速率和细胞需求速率之间的平衡建立。代谢产物如乳酸通过逆向途径除去。因此，离供给源最远的营养物的浓度可能很低;在健康动物的椎间盘中测得的氧浓度低至1%。虽然梯度在人类身上不易测量，但可以计算。手术患者的实测浓度与计算值一致。
The metabolic environment of disc cells is governed by the avascular nature of the tissue. Because cellular energy metabolism occurs mainly through glycolysis, the disc cells require glucose for survival and produce lactic acid at high rates. Oxygen is also necessary for cellular activity, although not for survival; its pathway of utilization is unclear. Because the tissues are avascular, disc cells depend on the blood supply at the margins of the discs for their nutrients. The nucleus and inner anulus of the disc are supplied by capillaries that arise in the vertebral bodies, penetrate the subchondral bone, and terminate at the bone-disc junction. Small molecules such as glucose and oxygen then reach the cells by diffusion under gradients established by the balance between the rate of transport through the tissue to the cells and the rate of cellular demand. Metabolites such as lactic acid are removed by the reverse pathway. The concentrations of nutrients farthest from the source of supply can thus be low; oxygen concentrations as low as 1% have been measured in the discs of healthy animals. Although gradients cannot be measured easily in humans, they can be calculated. Measured concentrations in surgical patients are in agreement with calculated values.