Kanda Kenro
Department of Central Nervous System, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan.
Microsc Res Tech. 2002 Nov 15;59(4):301-5. doi: 10.1002/jemt.10208.
The effects of life-long food restriction on motoneuronal cell death with advancing age was studied in male Fischer rats, which had access to food only 3 days a week after weaning (FR rats). Motoneurons innervating the medial gastrocnemius muscle were labeled with retrogradely transported HRP. The number of labeled motoneurons in FR rats and rats fed ad libitum (AL rats) was similar at the age of 16 months (131.8 +/- 1.7 for FR rats vs. 133.8 +/- 4.5 for AL rats). However, at 28 months of age, AL rats had less labeled motoneurons compared to FR rats (117.0 +/- 2.4 for FR rats vs. 124.3 +/- 7.0 for FR rats). The number of type I muscle fibers in the medial gastrocnemius muscle increased significantly in AL rats during the period from 16 to 28 months of age, which might reflect motor unit reorganization following retraction of axons and/or death of innervating motoneurons. FR rats did not show statistically significant alteration. These findings were also true for the data compiled from several different experiments including those conducted for primarily different purposes in our laboratory. The results suggest that life-long food restriction retards motoneuronal cell death occurring with advancing age.
在雄性Fischer大鼠中研究了终身食物限制对随着年龄增长运动神经元细胞死亡的影响，这些大鼠在断奶后每周仅能进食3天（FR大鼠）。用逆行转运的辣根过氧化物酶（HRP）标记支配腓肠肌内侧的运动神经元。在16个月大时，FR大鼠和自由进食大鼠（AL大鼠）中标记的运动神经元数量相似（FR大鼠为131.8±1.7，AL大鼠为133.8±4.5）。然而，在28个月大时，与FR大鼠相比，AL大鼠中标记的运动神经元较少（FR大鼠为117.0±2.4，AL大鼠为124.3±7.0）。在16至28个月龄期间，AL大鼠腓肠肌内侧的I型肌纤维数量显著增加，这可能反映了轴突回缩和/或支配运动神经元死亡后的运动单位重组。FR大鼠未显示出统计学上的显著变化。从包括我们实验室主要为不同目的进行的几个不同实验收集的数据来看，这些发现也是如此。结果表明，终身食物限制可延缓随着年龄增长而发生的运动神经元细胞死亡。
