Turner A S, Athanasiou K A, Zhu C F, Alvis M R, Bryant H U
Department of Clinical Sciences, Colorado State University, Ft. Collins 80523, USA.
Osteoarthritis Cartilage. 1997 Jan;5(1):63-9. doi: 10.1016/s1063-4584(97)80032-5.
Cartilage is a sex-hormone-sensitive tissue but the role of estrogen in the pathogenesis of osteoarthritis (OA) remains controversial. In this study, intrinsic material properties and thickness of articular cartilage of the knee joint of ovariectomized (OVX) and estrogen-treated sheep were measured. Skeletally mature ewes (N = 36, same breed, same housing 4-5 years old) were divided into; sham treated (n = 9), OVX (N = 13), OVX plus one estradiol implant (OVXE; N = 10) and OVX plus two estradiol implants (OVX2E; N = 4). Twelve months following sham procedure or OVX, sheep were euthanized and articular cartilage from a total of 216 points in the left femorotibial (knee) joints was tested for aggregate modulus, Poisson's ratio, permeability, thickness and shear modulus (six sites per sheep). When all of the sites in each knee were grouped together, OVX had a significant effect on articular cartilage. The sham cartilage of all sites grouped together had a larger aggregate modulus (P = 0.001) and a larger shear modulus (P = 0.054) than the OVX tissue. No statistically significant differences were seen for permeability and thickness between OVX, sham, OVXE and OVX2E. Differences existed in biomechanical properties at the different sites that were tested. Overall, no one location tended to be lowest or highest for all variables. This biomechanical study suggests that OVX may have a detrimental effect on the intrinsic material properties of the articular cartilage of the knee, even though the cartilage of the OVX animals appeared normal. Treatment with estradiol implants ameliorated these deleterious effects and may have helped maintain the tissue's structural integrity. Our study supports epidemiological studies of OA in women after menopause. The protective effect of estrogen and it's therapeutic effect remain to be further defined. This model may allow the relationship of estrogen and estrogen antagonists to be studied in greater detail, and may be valuable for the study of the pathogenesis and therapies of OA of postmenopausal women, particularly in its early stages.
软骨是一种对性激素敏感的组织，但雌激素在骨关节炎（OA）发病机制中的作用仍存在争议。在本研究中，对去卵巢（OVX）和接受雌激素治疗的绵羊膝关节软骨的内在材料特性和厚度进行了测量。将骨骼成熟的母羊（N = 36，同一品种，4 - 5岁，饲养条件相同）分为：假手术组（n = 9）、OVX组（N = 13）、OVX加一枚雌二醇植入物组（OVXE；N = 10）和OVX加两枚雌二醇植入物组（OVX2E；N = 4）。在假手术或OVX术后12个月，对绵羊实施安乐死，并对左股骨胫（膝）关节总共216个点的关节软骨进行聚集模量、泊松比、渗透率、厚度和剪切模量测试（每只绵羊6个部位）。当将每个膝关节的所有部位归为一组时，OVX对关节软骨有显著影响。所有部位归为一组的假手术组软骨比OVX组组织具有更大的聚集模量（P = 0.001）和更大的剪切模量（P = 0.054）。在OVX组、假手术组、OVXE组和OVX2E组之间，渗透率和厚度未见统计学显著差异。所测试的不同部位的生物力学特性存在差异。总体而言，所有变量在任何一个位置都没有呈现出最低或最高的趋势。这项生物力学研究表明，OVX可能对膝关节软骨的内在材料特性产生有害影响，尽管OVX动物的软骨看起来正常。雌二醇植入物治疗改善了这些有害影响，并可能有助于维持组织的结构完整性。我们的研究支持绝经后女性OA的流行病学研究。雌激素的保护作用及其治疗效果仍有待进一步明确。该模型可能有助于更详细地研究雌激素及其拮抗剂之间的关系，对于研究绝经后女性OA的发病机制和治疗方法可能具有重要价值，尤其是在早期阶段。
