Degens H, Turek Z, Hoofd L J, Van't Hof M A, Binkhorst R A
Department of Physiology, University of Nijmegen, The Netherlands.
J Anat. 1992 Jun;180 ( Pt 3)(Pt 3):455-63.
Compensatory hypertrophy of the plantaris muscle was obtained by denervation of its synergists. This hypertrophy is characterised by a 32% increase in muscle mass. The muscle consists of type I and IIa (oxidative), and IIb (glycolytic) fibres. Fibres of all types were enlarged in hypertrophied muscles and the proportion of type I fibres was increased. We investigated the capillarisation after hypertrophy as related to fibre type. In order to obtain this information a new technique was used, capable of estimating not only the traditional overall capillary density (CD) but also an index of heterogeneity in capillary spacing (LogSD), the 'local capillary to fibre ratio' (LCFR), obtained separately for each muscle fibre type, and finally a capillary density for each respective fibre type, the 'capillary fibre density' (CFD). It was found in both control and hypertrophied muscles that CD was higher in the deep (few IIb fibres) than in the superficial part of the muscle (considerable number of IIb fibres). The LogSD was lower, indicating less heterogeneity, in the deep than in the superficial part of the muscle. The LCFR and CFD of each fibre type was greater in the deep than in the superficial region of both control and hypertrophied muscles. Furthermore the CFD and LCFR were larger in type I and IIa fibres than in IIb fibres in each region of control and hypertrophied muscles. In hypertrophied muscles the CD was not significantly different from that of control muscles. However, LCFR of all fibre types was increased significantly in hypertrophied muscles as compared with controls, demonstrating capillary proliferation. The decreased CFD of type I and IIa fibres in the deep region of hypertrophied muscles as compared with controls suggests that here the capillary proliferation lags behind the increase in muscle mass. Endurance training had no significant effects for any region in any of the indices that were used.
通过使其协同肌去神经支配获得了比目鱼肌的代偿性肥大。这种肥大的特征是肌肉质量增加32%。该肌肉由I型和IIa型（氧化型）以及IIb型（糖酵解型）纤维组成。在肥大的肌肉中，所有类型的纤维都增大了，并且I型纤维的比例增加。我们研究了肥大后与纤维类型相关的毛细血管化情况。为了获取这些信息，采用了一种新技术，该技术不仅能够估计传统的总体毛细血管密度（CD），还能估计毛细血管间距的异质性指数（LogSD）、分别针对每种肌肉纤维类型获得的“局部毛细血管与纤维比率”（LCFR），最后是每种相应纤维类型的毛细血管密度，即“毛细血管纤维密度”（CFD）。发现在对照肌肉和肥大肌肉中，深层（IIb纤维较少）的CD均高于肌肉表层（IIb纤维数量较多）。肌肉深层的LogSD较低，表明异质性较小。对照肌肉和肥大肌肉的深层中，每种纤维类型的LCFR和CFD均大于表层区域。此外，在对照肌肉和肥大肌肉的每个区域中，I型和IIa型纤维的CFD和LCFR均大于IIb型纤维。在肥大肌肉中，CD与对照肌肉相比无显著差异。然而，与对照相比，肥大肌肉中所有纤维类型的LCFR均显著增加，表明有毛细血管增生。与对照相比，肥大肌肉深层区域I型和IIa型纤维的CFD降低，这表明此处毛细血管增生落后于肌肉质量的增加。耐力训练对所使用的任何指标的任何区域均无显著影响。
