Chen H, Yao X F, Emura S, Shoumura S
Department of Anatomy, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Tissue Cell. 2006 Oct;38(5):325-35. doi: 10.1016/j.tice.2006.08.001. Epub 2006 Sep 28.
SAMP6, a substrain of senescence-accelerated mouse, was developed as an animal model for senile osteoporosis. Previously we observed age-related changes of the bone in SAMP6. In the present study, we investigated the morphology of the skeletal muscle, tendon and periosteum in SAMP6 and age-matched normal mouse SAMR1. We did not find any significant differences between SAMR1 and SAMP6 at 1 and 2 months of age. As compared with SAMR1, the cross-sectional area of type I and type II muscle fibers of the soleus muscle were significantly low in SAMP6 at 8 months of age. The projections in the interface of the muscle-tendon junctions were significantly decreased in SAMP6 at 8 months of age. The number of fibroblasts and the diameter of the tendon collagen fibers in Achilles fiber were significantly reduced in SAMP6 at 8 months of age. The diameter of Sharpey's fiber reduced in SAMP6 at 5 and 8 months of age. Some chondrocytes in the insertions of Achilles tendon and some osteogenic cells in the periosteum showed degenerative changes in SAMP6 at 5 and 8 months of age. The pronounced degenerative changes were detected in the skeletal muscle, muscle-tendon junction, tendon, tendon-bone interface and periosteum in SAMP6 with age. These findings indicated the atrophy of skeletal muscle, degeneration of tendon and periosteum in SAMP6, which may be involved in the bone loss for senile osteoporosis.
SAMP6是衰老加速小鼠的一个亚系，作为老年性骨质疏松症的动物模型而培育。此前我们观察到了SAMP6骨骼的年龄相关变化。在本研究中，我们调查了SAMP6以及年龄匹配的正常小鼠SAMR1的骨骼肌、肌腱和骨膜的形态。在1月龄和2月龄时，我们未发现SAMR1和SAMP6之间存在任何显著差异。与SAMR1相比，8月龄SAMP6比目鱼肌I型和II型肌纤维的横截面积显著降低。8月龄SAMP6的肌腱结合处界面的突起显著减少。8月龄SAMP6跟腱中纤维母细胞数量和肌腱胶原纤维直径显著降低。5月龄和8月龄SAMP6的沙比纤维直径减小。5月龄和8月龄SAMP6跟腱附着处的一些软骨细胞和骨膜中的一些成骨细胞出现退行性变化。随着年龄增长，SAMP6的骨骼肌、肌腱结合处、肌腱、肌腱-骨界面和骨膜出现明显的退行性变化。这些发现表明SAMP6存在骨骼肌萎缩、肌腱和骨膜退变，这可能与老年性骨质疏松症的骨质流失有关。
