Urban J P, McMullin J F
University Laboratory of Physiology, Oxford University, England.
Spine (Phila Pa 1976). 1988 Feb;13(2):179-87. doi: 10.1097/00007632-198802000-00009.
The fluid content of the intervertebral disc is important in determining its mechanical response and also its transport and biologic properties. Fluid content depends on the proteoglycan content of the tissue and on the relationship of the external load to the disc's swelling pressure. The influence of proteoglycan content and external load on the hydration of nuclei from 32 human lumbar discs was measured. Swelling pressure of the same specimens was measured by equilibrium dialysis. The influence of age (14-91 years) and spinal level was noted. Proteoglycan content of the discs fell with age, and for all spines tested, proteoglycan content was lowest in the L5-S1 disc; no systematic change in collagen content was found. The hydration of the discs, as received, also fell with increase in age; in each complete lumbar spine tested, the L1-L2 and the L5-S1 discs had the lowest hydration at postmortem examination. As the stress applied to the discs was increased, hydration decreased. Although a stress of 0.10-0.23 MPa maintained the disc slices at their postmortem hydration, under a stress of about 0.6-0.8 MPa, most discs lost 40-60% of their initial fluid. The relationship between change in hydration and swelling pressure was found to depend on the composition of the disc rather than on age or degree of degeneration; the relationship between equilibrium hydration and swelling pressure could be predicted satisfactorily for a disc of known collagen and proteoglycan content.
椎间盘的液体含量对于确定其力学响应以及运输和生物学特性至关重要。液体含量取决于组织中的蛋白聚糖含量以及外部负荷与椎间盘肿胀压力之间的关系。测量了蛋白聚糖含量和外部负荷对32个成人腰椎间盘髓核水化的影响。通过平衡透析测量相同标本的肿胀压力。记录了年龄（14 - 91岁）和脊柱节段的影响。椎间盘的蛋白聚糖含量随年龄下降，并且在所有测试的脊柱节段中，L5 - S1椎间盘的蛋白聚糖含量最低；未发现胶原蛋白含量有系统性变化。所接收的椎间盘的水化程度也随年龄增加而下降；在每个完整的腰椎测试中，L1 - L2和L5 - S1椎间盘在尸检时水化程度最低。随着施加在椎间盘上的应力增加，水化程度降低。尽管0.10 - 0.23 MPa的应力可使椎间盘切片保持其尸检时的水化状态，但在约0.6 - 0.8 MPa的应力下，大多数椎间盘会失去其初始液体的40 - 60%。发现水化变化与肿胀压力之间的关系取决于椎间盘的组成，而非年龄或退变程度；对于已知胶原蛋白和蛋白聚糖含量的椎间盘，平衡水化与肿胀压力之间的关系可以得到令人满意的预测。
