Alterations in enzyme histochemical characteristics of the masseter muscle caused by long-term soft diet in growing rabbits
Alterations in enzyme histochemical characteristics of the masseter muscle caused by long-term soft diet in growing rabbits
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DOI：
10.1111/j.1601-0825.2004.01020.x
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发表时间：
2004-09-01
期刊：
影响因子：
3.8
通讯作者：
Sano, K
中科院分区：
文献类型：
--
作者：
Kitagawa, Y;Mitera, K;Sano, K
目的：近年来，年轻人越来越倾向于摄入易咀嚼的食物，咀嚼时间越来越少。本研究的目的是探讨组织化学的影响，长期的软食对咬肌生长rabbits.MATERIALS和METHODS：12只年轻的日本雄性白色兔分为两组（n = 6）断奶（出生后1个月），喂养固体饮食（对照组）或粉末饮食（软食组）。实验期为6个月。咬肌浅层和深层的咬肌纤维组织化学分为1、2A、2B和2C型。与对照组相比，软食组的深咬肌1型纤维横截面积占总面积的比例显著降低（软食组和对照组分别为6.3%和10.1%），2A型纤维显著更多（74.0% vs 50.3%），2B型纤维显著更少（4.3% vs 12.5%）。然而，两组之间的纤维大小没有差异。NADH-四唑还原酶（NADH-TR）的咬肌反应较低的软饮食组，反映了较低的氧化capability.CONCLUSIONS：这些研究结果表明，功能活动的改变有助于选择性废用影响的1型和2B型纤维，并由此增加2A型纤维。这项研究表明，长期改变颌骨功能诱导的软饮食可以导致咬肌的适应。
OBJECTIVE: Recently young people have an increasing tendency to intake an easily chewable diet and spend less time on mastication. The aim of the present study was to investigate the histochemical effects of long-term soft diet on the masseter muscle in growing rabbits.MATERIALS AND METHODS: Twelve young male Japanese white rabbits were divided into two groups (n = 6 each) at weaning (1 month after birth) and fed a solid diet (control group) or a powder diet (soft-diet group). The duration of the experimental period was 6 months. Masseter fibers from the superficial and the deep portions were histochemically defined as type 1, 2A, 2B, or 2C fibers.RESULTS: As compared with that of the control, the deep masseter of the soft-diet group showed a significantly lower ratio of type 1 fiber cross-sectional area to total area (6.3 and 10.1% for the soft-diet and control group, respectively), significantly more type 2A fibers (74.0% vs 50.3%) and significantly fewer type 2B fibers (4.3% vs 12.5%). However, fiber size did not differ between the two groups. NADH-tetrazolium-reductase (NADH-TR) of the masseter was less reactive in the soft-diet group, reflecting a lower oxidative capacity.CONCLUSIONS: These findings indicate that the alteration of the functional activities contributed to selective disuse influences on the type 1 and type 2B fibers, and a resultant increase in type 2A fibers. This study suggests that long-term alteration of jaw function induced by a soft diet can lead to adaptations of the masseter muscle.