Force-velocity characteristics and metabolism of carp muscle fibres following temperature acclimation.
Force-velocity characteristics and metabolism of carp muscle fibres following temperature acclimation.
复制标题
温度驯化后鲤鱼肌纤维的力-速度特性和代谢。
DOI：
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发表时间：
1985
影响因子：
2.8
通讯作者：
W. Driedzic
中科院分区：
文献类型：
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作者：
I. Johnston;B. Sidell;W. Driedzic
将体重1 kg的鲤鱼(Cyprinus Carpio L.)驯化到7~8℃(冷驯组)和23~24℃(温驯组)的水温中1~2个月。从肌肉中分离出单一的快纤维和小束的慢纤维，并对其进行化学剥皮。在7℃和23℃下测定了鲤鱼肌肉纤维的力-速度(P-V)特性。鲤鱼肌肉纤维的收缩特性取决于驯化温度。温习服组慢肌纤维的最大等长张力(P0，kNm-2)分别为47+/-6和+/-5，快肌纤维的最大等长张力(P0，kNm-2)分别为76+/-10和209+/-21。最大收缩速度(Vmax，肌肉长度-1)在7℃时为0.4+/-0.05和1.5+/-0.1(慢纤维)，在23℃时为0.6+/-0.04和1.9+/-0.4(快纤维)。所有值代表平均+/-S.E.从冷习服组分离的慢肌纤维和快肌纤维在7℃时的P0和Vmax大约高1.5-2.0倍。来自7℃驯化鲤鱼的纤维在23℃最大激活后不能完全松弛。由此产生的钙不敏感力成分(50-70%P0)与异常的交叉桥连接和非常慢的收缩速度的发展有关。与能量代谢相关的酶的活性测定是在15℃的常温下进行的，冷驯鱼慢肌中电子传递系统(细胞色素氧化酶)、柠檬酸循环(柠檬酸合成酶)、脂肪酸代谢(肉碱棕榈酰转移酶、β-羟基酰辅酶A脱氢酶)和有氧葡萄糖利用(己糖激酶)等标志性酶的活性比温驯鱼高30-60%。快速肌肉中细胞色素氧化酶和柠檬酸合成酶的活性也在低温习服后升高。结论是，鲤鱼骨骼肌输出的机械功率的热补偿伴随着在低温下提供有氧产生的ATP的潜力的增加。
Common carp (Cyprinus carpio L.), 1 kg body weight, were acclimated for 1-2 months to water temperatures of either 7-8 degrees C (cold-acclimated group) or 23-24 degrees C (warm-acclimated group). Single fast fibres and small bundles of slow fibres were isolated from the myotomal muscles and chemically skinned. Force-velocity (P-V) characteristics were determined at 7 degrees C and 23 degrees C. The contractile properties of carp muscle fibres are dependent on acclimation temperature. In the warm-acclimated group maximum isometric tensions (P0, kN m-2) are 47 +/- 6 and 64 +/- 5 for slow muscle fibres and 76 +/- 10 and 209 +/- 21 for fast muscle fibres at 7 degrees C and 23 degrees C, respectively. Maximum contraction velocities (Vmax, muscle lengths-1), are 0.4 +/- 0.05 and 1.5 +/- 0.1 at 7 degrees C (slow fibres) and 0.6 +/- 0.04 and 1.9 +/- 0.4 at 23 degrees C (fast fibres). All values represent mean +/- S.E. P0 and Vmax at 7 degrees C are around 1.5-2.0 times higher for slow and fast muscle fibres isolated from the cold-acclimated group. Fibres from 7 degrees C-acclimated carp fail to relax completely following maximal activations at 23 degrees C. The resulting Ca-insensitive force component (50-70% P0) is associated with the development of abnormal crossbridge linkages and very slow contraction velocities. Activities of enzymes associated with energy metabolism were determined at a common temperature of 15 degrees C. Marker enzymes of the electron transport system (cytochrome oxidase), citric acid cycle (citrate synthase), fatty acid metabolism (carnitine palmitoyl transferase, beta-hydroxyacyl CoA dehydrogenase) and aerobic glucose utilization (hexokinase) have 30-60% higher activities in slow muscle from cold-acclimated than from warm-acclimated fish. Activities of cytochrome oxidase and citrate synthase in fast muscle are also elevated following acclimation to low temperature. It is concluded that thermal compensation of mechanical power output by carp skeletal muscle is matched by a concomitant increase in the potential to supply aerobically-generated ATP at low temperatures.