Fernandez X, Lefaucheur L, Candek M
INRA - Station de Recherches Porcines, Saint-Gilles, 35590 L'Hermitage, France.
Meat Sci. 1995;41(2):225-35. doi: 10.1016/0309-1740(94)00059-g.
The present experiment was designed to compare two classifications of myofibres in samples of muscles longissimus lumborum (LL) and semispinalis capitis (SC) taken at slaughter from 56 Large White pigs. Comparisons were made for the percentage and histological characteristics of the different types of myofibres and for the photometric determination of glycogen using periodic acid schiff (PAS) staining. Computerized image analysis was used (i) to classify the fibres on the basis of myosin ATPase activity [Brooke and Kaiser (1970) Arch. Neurol.23, 3669; types I, IIA and HB], or by combination of myosin ATPase and succino-dehydrogenase (SDH) activities [Ashmore and Doerr (1971) Exp. Neurol.31, 408: types βR, αR, and αW] and (ii) to compute the PAS staining luminance in individual fibres. Glycogen and related metabolites were determined in muscle homogenates using enzymatic techniques. The LL showed significantly higher glycogen and lactate contents than the SC and a significantly lower average PAS staining luminance (indicative of higher glycogen content). The LL was composed predominantly of fast-twitch (89%) and white (77.3%) fibres. The SC contained mainly red (61.1%) and fast-twitch (59.3%) fibres. In both muscles, the comparison of the two classifications indicates that all type I fibres showed high SDH activity and were therefore typed as βR in Ashmore and Doerr's classification. However, in the LL, approximately 7% of the type IIB fibres showed a marked SDH activity and were thus typed as αR in Ashmore and Doerr's classification. Furthermore, significant differences were found between these two types for the cross sectional area of the fibres. In the SC, no significant differences were found for the pairwise comparisons of corresponding types between the two classifications. According to the photometric determination, fast-twitch glycolytic fibres of the LL showed significantly higher glycogen content than red (fast- and slow-twitch) fibres, whereas in the SC, slow-twitch fibres had significantly lower glycogen levels than fast-twitch (red and white fibres). Corresponding types between the two classifications showed similar glycogen levels.
本实验旨在比较56头大白猪屠宰时采集的腰大肌（LL）和头半棘肌（SC）样本中两种肌纤维分类。对不同类型肌纤维的百分比和组织学特征以及使用过碘酸希夫（PAS）染色法进行糖原的光度测定进行了比较。使用计算机图像分析（i）根据肌球蛋白ATP酶活性[布鲁克和凯泽（1970年）《神经病学文献》23, 3669；I型、IIA型和IIB型]或通过肌球蛋白ATP酶和琥珀酸脱氢酶（SDH）活性的组合[阿什莫尔和多尔（1971年）《实验神经病学》31, 408：βR型、αR型和αW型]对纤维进行分类，以及（ii）计算单个纤维的PAS染色亮度。使用酶技术测定肌肉匀浆中的糖原和相关代谢物。LL的糖原和乳酸含量显著高于SC，且平均PAS染色亮度显著较低（表明糖原含量较高）。LL主要由快肌纤维（89%）和白色纤维（77.3%）组成。SC主要包含红色纤维（61.1%）和快肌纤维（59.3%）。在两块肌肉中，两种分类的比较表明，所有I型纤维均显示出高SDH活性，因此在阿什莫尔和多尔的分类中被归类为βR型。然而，在LL中，约7%的IIB型纤维显示出显著的SDH活性，因此在阿什莫尔和多尔的分类中被归类为αR型。此外，发现这两种类型在纤维横截面积方面存在显著差异。在SC中，两种分类中相应类型的两两比较未发现显著差异。根据光度测定，LL的快肌糖酵解纤维的糖原含量显著高于红色（快肌和慢肌）纤维，而在SC中，慢肌纤维的糖原水平显著低于快肌（红色和白色纤维）。两种分类中的相应类型显示出相似的糖原水平。
