Qiu Y, Yao J, Wu X, Zhou B, Shao H, Hua T, Xiong Z, Tang G
Department of Radiology, Shanghai Tenth People's Hospital of Tongji University, Shanghai, 200072, China.
Osteoporos Int. 2015 Mar;26(3):1081-92. doi: 10.1007/s00198-014-2933-9. Epub 2014 Oct 22.
This study aims to longitudinally assess the effect of oxytocin on bone and bone fat masses using micro-CT, in vivo magnetic resonance spectroscopy (MRS), and histopathological adipocyte quantification. Early in vivo oxytocin (OT) treatment to the osteoporosis (OP) rabbit model may reliably inhibit bone degeneration and reduce bone marrow fat accumulation by decreasing marrow adipocyte size and density.
This study aims to longitudinally assess the effect of early OT treatment on bone and bone fat masses in a rabbit OP model by comparing the results of MRS and micro-CT with histopathological findings.
Sixty 20-week-old female rabbits were randomly assigned into three groups. The control and OP groups were subjected to either sham surgery or bilateral ovariectomy (OVX). The OT group was subcutaneously injected with OT daily from the second week after OVX for 8 weeks. The left proximal femurs of the rabbits were evaluated through MRS, micro-CT, and histopathological examination at 0, 4, 8, 10, and 12 weeks after operation. Differences in fat fraction (FF) values, micro-CT parameters, and calculated pathological marrow adipocytes among three groups were analyzed.
The FF values of the OP group significantly increased (p = 0.019), but the tissue mineral density (TMD) decreased (p = 0.037) from eighth week compared with those of the control group. The FF values of the OT group significantly decreased (p = 0.044), but the TMD values increased (p = 0.042) from eighth week compared with those of the OP group. The adypocyte diameter of the OT group significantly decreased (p = 0.041) from eighth week and then adypocyte density did so too from tenth week, compared with those of the OP group at the same time point. No difference in adypocyte calculation was found between the OT and control groups until the 12th week after operation.
Early in vivo OT treatment slowed down bone deterioration and reduced bone marrow adiposity accumulation in a rabbit OP model, which is consistent with pathologic findings. OT treatment is a promising preventive OP therapy.
本研究旨在使用微型计算机断层扫描（micro-CT）、体内磁共振波谱（MRS）和组织病理学脂肪细胞定量法，纵向评估催产素对骨骼和骨脂肪量的影响。对骨质疏松症（OP）兔模型进行早期体内催产素（OT）治疗，可通过减小骨髓脂肪细胞大小和密度，可靠地抑制骨质退化并减少骨髓脂肪堆积。
本研究旨在通过比较MRS和micro-CT的结果与组织病理学发现，纵向评估早期OT治疗对兔OP模型中骨骼和骨脂肪量的影响。
将60只20周龄雌性兔子随机分为三组。对照组和OP组分别接受假手术或双侧卵巢切除术（OVX）。OT组在OVX后第二周开始每天皮下注射OT，持续8周。在术后0、4、8、10和12周，通过MRS、micro-CT和组织病理学检查对兔子的左近端股骨进行评估。分析三组之间脂肪分数（FF）值、micro-CT参数和计算得出的病理性骨髓脂肪细胞的差异。
与对照组相比，OP组的FF值从第八周起显著增加（p = 0.019），但骨组织矿物质密度（TMD）降低（p = 0.037）。与OP组相比，OT组的FF值从第八周起显著降低（p = 0.044），但TMD值增加（p = 0.042）。与OP组在同一时间点相比，OT组的脂肪细胞直径从第八周起显著减小（p = 0.041），然后脂肪细胞密度从第十周起也显著减小。直到术后第12周，OT组和对照组之间在脂肪细胞计算方面均未发现差异。
在兔OP模型中，早期体内OT治疗减缓了骨质恶化并减少了骨髓脂肪堆积，这与病理结果一致。OT治疗是一种有前景的预防OP的疗法。
