骨髓腔內脂肪細胞在骨代謝過程中所扮演的角色是近年來的新興研究議題，研究結果對骨髓腔內脂肪細胞的評價尚未有定論。目的：本研究探討耐力運動及熱量限制介入對於雄性大鼠骨髓腔脂肪細胞與骨代謝、骨組織型態之影響。方法：本實驗以週齡26週雄性Sprague-Dawley (SD) 大鼠為實驗對象，依照控制組 (control group, CON)、耐力運動訓練 (endurance exercise, EXE) 及40%與20% 熱量限制 (caloric restriction, CR40%, CR20%) 等實驗設計分為四組，分別為CON (n=12)、EXE (n=12)、CR40% (n=12)、CR20% (n=12)。耐力運動組別的動物以16公尺/分鐘，每週訓練五天；熱量限制組的動物則是以控制組的每日飼料攝取量減少40%與20%為熱量限制，實驗介入期為9週。本研究分析所得之依變項數值採用單因子變異數分析 (one-way ANOVA) 以及單因子共變數分析 (one-way ANCOVA)（以體重為共變量）進行各組間的差異性比較，當p＜.05視為達顯著水準，則以Fisher’s LSD方法進行事後比較。結果：在體重方面，實驗介入後的第1.5~2週後，CR 40 %、CR 20% 及EXE組即顯著低於CON組。在骨髓腔的脂肪細胞、海綿骨靜態骨骼組織型態學與海綿骨骨密度等參數方面，各組間無論是以one-way ANOVA 或 ANCOVA進行統計分析，均未呈現顯著差異。在血液指標上面， CON組在瘦素 (leptin) 、胰島素(insulin)和三酸甘油脂 (TG) 顯著大於其他三組，CR20%與EXE在胰島素的表現上也顯著大於CR40%，血糖(glucose)方面，CR20%顯著高於CR40%與EXE，其他項目均未達顯著差異。結論：飲食限制與耐力運動訓練在改善能量代謝及減重後，並未進一步未造成成年骨髓腔脂肪細胞與各項骨質測量參數進一步的負面結果。

The role of bone marrow adipocyte in bone metabolism has been vigorously investigated in recently years and the results were controversial. Objective: The purpose of this study was to investigate the effects of endurance exercise and caloric restriction on morphology of bone marrow adipocytes, spongy bone histomorphometry and densitometry and bone metabolism in adult male rats. Methods: Forty eight male Sprague-Dawley (SD) rats (26-week-old) were randomly assigned into four groups, which were the control (CON, n=12), 40 % caloric restriction (CR40%, n=12), 20 % caloric restriction (CR20%, n=12) and endurance exercise (EXE, n=12) groups. Animals of the CR40% and CR20% groups respectively subjected to 40% and 20% dietary restriction according to the average daily intake in the CON group. Animals of the EXE group subjected to treadmill run at a speed of 16 m/min, 1 hour/day and five days a week. After nine weeks of experimental intervention, the animals were euthanized, and tibiae and blood samples were collected for spongy bone histomorphometry and densitometry analyses, bone marrow adipocyte morphology analyses and serum bone marker assays. Statistical methods of One-way ANOVA and one-way ANCOVA were used for comparing the difference among groups. Result: In body weight, the CR40%, CR20%, EXE group showed significantly less body weight compared to the CON group after 1~1.5 weeks of experimental interventions. In order to investigate bone metabolic status after 9 weeks of experimental intervention, several related serum markers including collagen type 1 cross-linked C-telopeptide (CTX-1), procollagen type 1 amino-terminal propeptide (P1NP), triglycerides (TGs), leptin, and cholesterol were measured. In serum leptin, the CR40%, CR20%, EXE groups demonstrated significantly lower values when compared to the CON groups (p<0.05). In addition, serum triglyceride (TG) and insulin was lower in the CR40% group as compared to the CR20% and EXE groups (p<0.05). Serum glucose, the CR20% group demonstrated significantly higher values when compared to the CR40% and EXE groups (p<0.05). In bone marrow adipocytes, histomorphometric and densitometric indices, no significant difference was shown among all groups. Conclusion: In spite of the favourable changes induced by caloric restriction and endurance exercise in body weight and energy profile, no detrimental effects was shown in bone marrow adipocytes as well as various bone mineral measurements.

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