Reddy G Kesava
Department of Physical Therapy and Rehabilitation Sciences, University of Kansas Medical Center, Kansas City 66160-760, USA.
J Orthop Res. 2003 Jul;21(4):738-43. doi: 10.1016/S0736-0266(03)00006-8.
Glycation induced crosslinking of connective tissue collagen is thought to be involved in the pathogenesis of various disorders associated with diabetes and aging. Although the formation of the glycation related collagen crosslinks appears to be universal for all tissues, currently it is unknown whether differences exist between soft and hard tissue biomechanics in response to glucose-mediated in vitro glycation. In this study, the impact of non-enzymatic glycation was investigated on tendons and bones, using them as models for soft and hard tissue respectively. Achilles tendons from rabbits, and femur and tibia from rats, were subjected to in vitro glycation with glucose. Sixty days following glycation, the matrix integrity of the tendons and bones was evaluated and compared with the respective non-glycated tissue (n=10 in each group). The results revealed that the impact of glycation was significant on the tendon but not on the bone. Measurements of the biomechanical stability of glycated tendons indicated a significant increase in maximum load (21%), Young's modulus of elasticity (72%), energy to yield (35%) and toughness (68%) compared to the non-glycated tendons. No significant differences were found in breaking strength, bending stiffness, energy to yield and toughness between glycated and non-glycated femurs or tibias. The deformation of both soft and hard tissue was unaffected by the glycation. Measurements at ultimate tissue failure (break point) revealed that glycated tendons bore significantly higher load and energy absorption than non-glycated tendons. In contrast, the deformation of the glycated tendons at break point was considerably reduced as compared to control tendons. However, glycation had no significant effects on the hard tissue biomechanical properties at break point. The results of this study demonstrate that in vitro glycation influences the biomechanical properties of soft tissue but not hard tissue.
糖化诱导的结缔组织胶原蛋白交联被认为与糖尿病和衰老相关的各种疾病的发病机制有关。尽管糖化相关胶原蛋白交联的形成似乎在所有组织中都很普遍,但目前尚不清楚在体外葡萄糖介导的糖化反应中,软组织和硬组织的生物力学是否存在差异。在本研究中,分别以肌腱和骨骼作为软组织和硬组织的模型,研究了非酶糖化的影响。用葡萄糖对兔的跟腱以及大鼠的股骨和胫骨进行体外糖化。糖化60天后,评估肌腱和骨骼的基质完整性,并与各自的未糖化组织进行比较(每组n = 10)。结果显示,糖化对肌腱有显著影响,但对骨骼没有影响。与未糖化的肌腱相比,糖化肌腱生物力学稳定性的测量结果表明,最大负荷(21%)、杨氏弹性模量(72%)、屈服能量(35%)和韧性(68%)显著增加。糖化和未糖化的股骨或胫骨在断裂强度、弯曲刚度、屈服能量和韧性方面没有显著差异。软组织和硬组织的变形均不受糖化的影响。在组织最终失效(断裂点)时的测量结果显示,糖化肌腱承受的负荷和能量吸收显著高于未糖化的肌腱。相比之下,与对照肌腱相比,糖化肌腱在断裂点的变形明显减小。然而,糖化对硬组织在断裂点的生物力学性能没有显著影响。本研究结果表明,体外糖化会影响软组织的生物力学性能,但不会影响硬组织的生物力学性能。