Effect of vitamin K2 on three-dimensional trabecular microarchitecture in ovariectomized rats
Effect of vitamin K2 on three-dimensional trabecular microarchitecture in ovariectomized rats
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DOI：
10.1359/jbmr.2000.15.9.1810
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发表时间：
2000-09-01
影响因子：
6.2
通讯作者：
Iwamoto, Y
中科院分区：
文献类型：
--
作者：
Mawatari, T;Miura, H;Iwamoto, Y
据报道，Menatetrenone是一种含有四个异戊二烯单元的维生素K-2，可改善骨质疏松性骨丢失。本研究的目的是通过使用微计算机断层扫描（MCT）来阐明甲基烯雌酮对卵巢切除（OVX）大鼠三维（3D）小梁微结构的影响。选用42只13周龄雌性大鼠，分为4组：去卵巢组（OVX + MK-4）、去卵巢未处理组（OVX untreated）、假手术组（Sham + MK-4）、假手术组（Sham untreated）。OVX大鼠喂食缺钙饮食。在卵巢切除术后立即开始甲烯雌酮治疗，并将8周期间的平均甲烯雌酮口服摄入量调整为30 mg/kg BW/天。通过双能X线骨密度仪（DXA）和MCT评价右侧胫骨近端干骺端区域。使用骨体积分数、通过3D盒计数法计算的分形维数和通过拓扑分析确定的连接密度对重建的骨小梁体积进行参数分析。与OVX未处理组相比，Men atenone显著增加OVX + MK-4组的骨小梁体积、分形维数和连接性（p < 0.01）。我们的研究结果表明，在卵巢切除术后立即开始治疗时，给予8周的甲烯雌酮可以防止骨小梁体积及其连接性的丧失。尽管有这种明显的保护作用，但如果在小梁连接丧失后进行治疗干预，是否有可能重建小梁连接仍然是未知的。
Menatetrenone, a vitamin K-2 with four isoprene units, has been reported to improve osteoporotic bone loss. The purpose of this investigation was to clarify the effect of menatetrenone on the three-dimensional (3D) trabecular microarchitecture in ovariectomized (OVX) rats by using microcomputed tomography (MCT). Forty-two 13-week-old female rats were used and divided into four groups: the OVX (OVX + MK-4) group treated with menatetrenone, the (OVX untreated) group, the sham-operated (Sham + MK-4) group treated with menatetrenone, and the sham operated group not treated with menatetrenone (Sham untreated) group. OVX rats were fed a calcium-deficient diet. Menatetrenone treatment was begun just after the ovariectomy, and the mean menatetrenone oral intake over the 8-week period was adjusted to 30 mg/kg BW per day. The proximal metaphyseal region of the right tibia was evaluated by dual X-ray absorptiometry (DXA) and MCT. A parametric analysis of the reconstructed trabecular volume was carried out using bone volume fractions, the fractal dimension calculated by the 3D box-counting method, and the connectivity density as determined by topological analysis. Menatetrenone significantly increased the trabecular bone volume, fractal dimension, and connectivity in the OVX + MK-4 group compared with the OVX-untreated group (p < 0.01). Our results suggest that an 8-week administration of menatetrenone protects against the loss of trabecular bone volume and its connectivity when treatment is begun just after the ovariectomy. Despite this apparent protection, it remains unknown whether it is possible to reestablish trabecular connectivity if therapeutic intervention occurs after the trabecular connectivity has been lost.