An evaluation of the reliability of muscle fiber cross-sectional area and fiber number measurements in rat skeletal muscle.
An evaluation of the reliability of muscle fiber cross-sectional area and fiber number measurements in rat skeletal muscle.
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DOI：
10.1186/1480-9222-15-6
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发表时间：
2013-03-08
影响因子：
6.4
通讯作者：
Dawson-Hughes B
中科院分区：
文献类型：
--
作者：
Ceglia L;Niramitmahapanya S;Price LL;Harris SS;Fielding RA;Dawson-Hughes B
仅从大鼠后肢肌肉横截面中的一部分纤维估计肌纤维横截面积(肌肉纤维大小的测量)和纤维数量的可靠性尚未得到系统评估。这项研究检验了纤维横截面积平均值估计的可变性作为测量的纤维数量的函数，并测试了计算横截面中的纤维子集是否可以预测中年大鼠的总纤维数量。对23个月龄雄性Fisher 344×Brown挪威大鼠的比目鱼肌和指长伸肌(EDL)横切面进行肌原纤维ATPase活性染色，以识别肌纤维类型(I型[慢抽动]或II型[快抽动])和层粘连蛋白，以便于纤维横截面测量。我们勾画了1000到1600个单一肌肉纤维的周长，用于测量肌肉截面内的纤维横截面积。I型肌纤维的平均横截面积是基于比目鱼肌的横截面，比目鱼肌主要由I型肌纤维组成。II型肌纤维的平均横截面积是以EDL肌切片为基础的，EDL肌切片主要由II型肌纤维组成。自举重采样技术表明，I型和II型纤维横截面平均面积的抽样分布的变异性随着所测纤维数量的增加而减小并逐渐稳定，其中变异性在数量低于150根纤维时发生大幅下降。自举的I型纤维平均横截面积的变异系数低于II型。在相同的肌肉切片中，总纤维数与横截面上1、2、3和4个固定视野区域(10倍放大；1000×1500像素的大小/视野)内的纤维数进行比较。3~4个视野的纤维数(约占横截面积的15~20%)对总纤维数有较好的预测值(r=0.57~0.59，P=0.003)。这些数据描述了在这个大鼠模型中，当测量的纤维样本量增加到至少150个时，估计平均纤维横截面积的精确度提高的模式。对横截面中15%-20%的纤维进行计数，可以相当可靠地估计总纤维数量。
The reliability of estimating muscle fiber cross-sectional area (measure of muscle fiber size) and fiber number from only a subset of fibers in rat hindlimb muscle cross-sections has not been systematically evaluated. This study examined the variability in mean estimates of fiber cross-sectional area as a function of the number of fibers measured, and tested whether counting a subset of fibers in a cross-section could predict total fiber number in middle-aged rats. Soleus and extensor digitorum longus (EDL) muscle cross-sections from 23-month-old, male Fisher 344 x Brown Norway rats were stained for myofibrillar ATPase activity to identify muscle fiber type (either type I [slow-twitch] or II [fast-twitch]) and laminin to facilitate fiber cross-sectional measurements. We outlined the circumference of 1000 to 1600 single muscle fibers for measurement of fiber cross-sectional area within muscle sections. Mean type I fiber cross-sectional area was based on soleus muscle sections which were predominantly composed of type I muscle fibers. Mean type II fiber cross-sectional area was based on EDL muscle sections which were predominantly composed of type II muscle fibers. A bootstrapping resampling technique demonstrated that variability in sampling distribution of mean type I and II fiber cross-sectional areas decreased and gradually stabilized as the number of fibers measured increased with large declines in variability occurring at numbers below 150 fibers. Coefficients of variation for bootstrapped mean type I fiber cross-sectional areas were lower than for type II. In the same muscle sections, total fiber number was compared to fiber numbers within 1, 2, 3, and 4 fixed field areas (10x magnification; 1000 x 1500 pixels in size/field) on the cross-section. Fiber numbers from 3 to 4 fields (approximating 15 to 20% of the cross-section) provided a reasonably predictive value of total fiber number (r=0.57-0.59, P=0.003). These data describe a pattern of improved precision in estimating mean fiber cross-sectional area as sample size of fibers measured increases to at least 150 in this rat model. Counting 15-20% of the fibers in cross-sections provides a reasonably reliable estimate of the total fiber number.
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DOI：
10.1023/b:jure.0000021398.78327.39
发表时间：
2004-01-01
影响因子：
2.7
作者：
McCormick, KM;Burns, KL;Brazeau, GA
通讯作者：
Brazeau, GA
影响因子：
5.3
作者：
HOLLOSZY, JO;CHEN, M;YOUNG, JC
通讯作者：
YOUNG, JC
影响因子：
5.3
作者：
Varela, CR;Bengston, L;Forger, NG
通讯作者：
Forger, NG
影响因子：
3.3
作者：
Fisher, JS;Hasser, EM;Brown, M
通讯作者：
Brown, M
影响因子：
2.7
作者：
Piccone, CM;Brazeau, GA;McCormick, KM
通讯作者：
McCormick, KM