Carson J A, Alway S E
Department of Exercise Science, Ohio State University, Columbus 43210, USA.
Am J Physiol. 1996 Feb;270(2 Pt 1):C578-84. doi: 10.1152/ajpcell.1996.270.2.C578.
Stretch overload-induced activation of satellite cells in the anterior latissimus dorsi (ALD) muscle was examined in full-grown adult (12 wk old) and aged (90 wk old) Japanese quail. 5'-Bromo-2'-deoxyuridine (BrdU) constant-release pellets (0.22 mg BrdU.g body wt-1.day-1) were implanted subcutaneously before weighting the left wing of each bird. Nuclei that incorporated BrdU were localized by immunohistochemistry after 1 or 2 wk of stretch overload. Total fiber number was quantified by counting all fibers in a histological cross section from the midbelly of the ALD. Aging reduced increases in ALD mass and fiber number during 2 wk of stretch overload. Fiber proliferation in the ALD of aged birds also demonstrated an altered time course. The percentage of BrdU-positive nuclei associated with muscle fibers and the percentage of fibers associated with BrdU-positive nuclei did not differ between age groups. The altered time course of new fiber formation in the ALD of aged birds during 2 wk of stretch overload does not appear to be related to the capability to activate satellite cells.
在成年（12周龄）和老龄（90周龄）日本鹌鹑中，研究了拉伸过载诱导的背阔肌前束（ALD）卫星细胞的激活情况。在称量每只鸟的左翼重量之前，皮下植入5'-溴-2'-脱氧尿苷（BrdU）缓释微丸（0.22 mg BrdU·g体重-1·天-1）。在拉伸过载1周或2周后，通过免疫组织化学定位掺入BrdU的细胞核。通过计数来自ALD中腹部的组织学横截面中的所有纤维来量化总纤维数。衰老减少了拉伸过载2周期间ALD质量和纤维数量的增加。老龄鸟的ALD中的纤维增殖也表现出时间进程的改变。与肌纤维相关的BrdU阳性细胞核的百分比以及与BrdU阳性细胞核相关的纤维的百分比在不同年龄组之间没有差异。老龄鸟在拉伸过载2周期间ALD中新纤维形成的时间进程改变似乎与激活卫星细胞的能力无关。
