Contractile properties and protein isoforms of single fibres from the chicken pectoralis red strip muscle.
Contractile properties and protein isoforms of single fibres from the chicken pectoralis red strip muscle.
复制标题
鸡胸肌红条肌单纤维的收缩特性和蛋白质亚型。
DOI：
10.1113/jphysiol.1996.sp021403
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Moss,RL
中科院分区：
文献类型：
--
作者：
Reiser,PJ;Greaser,ML;Moss,RL
1. 测定了成年鸡胸大肌红条区单个肌纤维的收缩特性，并将其与胸大肌快白纤维和背前阔肌慢强直纤维的收缩特性进行了比较，其中一些红条区已知表达一种胚胎型肌球蛋白重链（MHC）。2. 红色条形纤维可分为快、慢两类。快速红条纤维的平均空载缩短速度（Vmax）约为快速白条纤维Vmax的一半。慢红条纤维的Vmax小于快红条纤维的20%，与ALD纤维的Vmax无显著差异。3. 快速红条纤维和快速白条纤维的张力产生能力，即最大等距张力/纤维横截面积（P0/CSA）是相同的。与快速红条纤维相比，慢红条纤维的P0/CSA约低30%，但与ALD纤维相比，慢红条纤维的P0/CSA高70%。4. 快速红条纤维的张力- pCa关系转移到较低的pCa值，表明与快速白色纤维相比，钙敏感性较低，这种差异与肌钙蛋白T异构体组成的差异有关。慢红条状纤维的张力- pCa关系与ALD纤维的张力- pCa关系无明显差异。5. 快速红条纤维和快速白条纤维的Vmax差异与这些纤维的MHC组成不同有关。6. 慢红条状纤维的肌原纤维蛋白异构体组成与ALD肌的慢强直纤维相同，两组纤维具有非常相似的收缩特性。
1. The contractile properties of single muscle fibres of the red strip region of adult chicken pectoralis major (PM) muscle, some of which are known to express an embryonic isoform of myosin heavy chain (MHC), were determined and compared with the properties of the fast white fibres of the PM and the slow tonic fibres of the anterior latissimus dorsi (ALD) muscle. 2. The red strip fibres could be classified into two groups, fast and slow. The mean velocity of unloaded shortening (Vmax) in fast red strip fibres was approximately half the Vmax of fast white fibres. Vmax of slow red strip fibres was less than 20% of the value for fast red strip fibres and was not different from Vmax of ALD fibres. 3. The tension‐generating ability, i.e. the maximal isometric tension/fibre cross‐sectional area (P0/CSA), was the same in fast red strip fibres and fast white fibres. P0/CSA was approximately 30% lower in slow red strip fibres compared with fast red strip fibres but was 70% greater in slow red strip fibres compared with ALD fibres. 4. The tension‐pCa relation of fast red strip fibres was shifted to lower pCa values, indicating a lower calcium sensitivity compared with fast white fibres, and this difference was associated with a difference in troponin T isoform composition. The tension‐pCa relation of slow red strip fibres was not different from that in ALD fibres. 5. The difference in Vmax between fast red strip fibres and fast white fibres was associated with different MHC compositions of these fibres. 6. The myofibrillar protein isoform composition of slow red strip fibres was identical to that of the slow tonic fibres of ALD muscle and these two groups of fibres had very similar contractile properties.