Metabolism of the intervertebral disc: Effects of low levels of oxygen, glucose, and pH on rates of energy metabolism of bovine nucleus pulposus cells
Metabolism of the intervertebral disc: Effects of low levels of oxygen, glucose, and pH on rates of energy metabolism of bovine nucleus pulposus cells
复制标题
DOI：
10.1097/01.brs.0000154619.38122.47
复制
发表时间：
2005-03-01
期刊：
影响因子：
3
通讯作者：
Urban, JPG
中科院分区：
文献类型：
--
作者：
Bibby, SRS;Jones, DA;Urban, JPG
研究设计.体外测量不同氧、葡萄糖和pH水平下分离的牛髓核细胞的代谢率。目的。获得椎间盘核细胞氧和葡萄糖浓度与pH之间相互作用的定量信息，以及氧和葡萄糖消耗率和乳酸产生率。椎间盘细胞依赖于椎间盘边缘血管的扩散来提供营养。供应的丧失被认为会导致椎间盘退变，但供应的丧失如何影响椎间盘中的营养物质浓度尚不清楚;通常只能计算椎间盘中的营养物质浓度，因为浓度测量是侵入性的。然而，直到有来自在体内椎间盘中发现的条件下的代谢率的测量的数据，才能做出现实的预测，即，在低水平的氧气、葡萄糖和pH下。代谢室的设计，以允许同时记录的氧气和葡萄糖的浓度和pH值。这些浓度进行电化学测量与定制的葡萄糖和氧气传感器;乳酸进行生化测量。分离牛髓核细胞并将其插入小室中，在葡萄糖、氧气和pH水平范围内同时测量氧气和葡萄糖消耗率以及乳酸产生率。有很强的代谢率和耗氧和pH值之间的相互作用。在大气中的氧水平，在pH值为6.2的耗氧率是在pH值为7.4的32%。在pH 7.4下，当氧浓度从21%降低到5%时，速率下降60%，但在pH 6.2下仅下降20%。乳酸产生和葡萄糖消耗速率也有类似的相互作用;我们发现糖酵解速率在低氧和葡萄糖浓度以及低pH值下下降。推导出的方程可以令人满意地预测营养物质和代谢物浓度对乳酸产生速率和氧消耗速率的影响。在空气中，在pH 7.4的椎间盘细胞代谢显着不同，发现在体内的椎间盘核，其中低水平的氧气，葡萄糖，和pH值共存。
Study Design. In vitro measurements of metabolic rates of isolated bovine nucleus pulposus cells at varying levels of oxygen, glucose, and pH.Objectives. To obtain quantitative information on the interactions between oxygen and glucose concentrations and pH, and the rates of oxygen and glucose consumption and lactic acid production, for disc nucleus cells.Summary of Background Data. Disc cells depend on diffusion from blood vessels at the disc margins for supply of nutrients. Loss of supply is thought to lead to disc degeneration, but how loss of supply affects nutrient concentrations in the disc is not known; nutrient concentrations within discs can normally only be calculated, because concentration measurements are invasive. However, realistic predictions cannot be made until there are data from measurements of metabolic rates at conditions found in the disc in vivo, i.e., at low levels of oxygen, glucose, and pH.Methods. A metabolism chamber was designed to allow simultaneous recording of oxygen and glucose concentrations and of pH. These concentrations were measured electrochemically with custom-built glucose and oxygen sensors; lactic acid was measured biochemically. Bovine nucleus pulposus cells were isolated and inserted into the chamber, and simultaneous rates of oxygen and glucose consumption and of lactic acid production were measured over a range of glucose, oxygen, and pH levels.Results. There were strong interactions between rates of metabolism and oxygen consumption and pH. At atmospheric oxygen levels, oxygen consumption rate at pH 6.2 was 32% of that at pH 7.4. The rate fell by 60% as oxygen concentration was decreased from 21 to 5% at pH 7.4, but only by 20% at pH 6.2. Similar interactions were seen for lactic acid production and glucose consumption rates; we found that glycolysis rates fell at low oxygen and glucose concentrations and low pH. Equations were derived that satisfactorily predict the effect of nutrient and metabolite concentrations on rates of lactic acid production rate and oxygen consumption.Conclusions. Disc cell metabolism in air and at pH 7.4 differs markedly from that found in the disc nucleus invivo, where low levels of oxygen, glucose, and pH all coexist.