Energy coupling to sodium transport in frog skeletal muscle.
Energy coupling to sodium transport in frog skeletal muscle.
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青蛙骨骼肌中钠转运的能量耦合。
DOI：
10.1152/ajpcell.1978.235.1.c25
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
E. Hays
中科院分区：
文献类型：
--
作者：
R. Connett;E. Hays
在刚分离的青蛙骨骼肌中，除了肌鞘苷敏感（SS）的钠流出外，钠流出的很大一部分是钠激活和肌鞘苷不敏感（SASI）的。测量了每一种成分与钠运动相关的代谢能，并计算了钠运动与肌肉中腺苷5'-三磷酸（ATP）水解之间的偶联。能源生产被醋酸碘和氰化物阻断。能量周转由磷酸肌酸（CrP）和ATP含量的变化估计，并以势能（PE = CrP + 2ATP）表示。代谢中毒后PE呈线性下降（6.3 μ mol/g.h）。代谢性中毒对钠外排的SS或SASI组分的大小没有影响。在2 h内，钠离子的移动和由SS组分引起的PE变化分别为4.35和1.66 μ mol/g.h，耦合系数为2.6。在2 h内，SASI组分移动的钠量与SS组分移动的钠量相似，但未观察到能量变化。因此，可以得出结论，SASI组分的钠运动不需要能量输入。
In addition to a strophanthidin-sensitive (SS) sodium efflux, a large component of the sodium efflux in freshly isolated frog skeletal muscle is sodium-activated and strophanthidin-insensitive (SASI). The amount of metabolic energy associated with sodium movement by each of these components was measured and the coupling between sodium movement and adenosine 5'-triphosphate (ATP) hydrolysis in muscle was calculated. Energy production was blocked by iodoacetate and cyanide. Energy turnover was estimated from the change in creatine phosphate (CrP) and ATP contents and expressed as potential energy (PE = CrP + 2ATP). After metabolic poisoning a linear fall of PE occurred (6.3 mumol/g.h). Metabolic poisoning had no effect on the magnitude of the SS or SASI components of sodium efflux. In 2 h the sodium moved, and PE change due to the SS component was 4.35 and 1.66 mumol/g.h, respectively, which gave a coupling factor of 2.6. The amount of sodium moved by the SASI component was similar to that moved by the SS component in 2 h whereas no energy change was observed. It was, therefore, concluded that sodium movement by the SASI component requires no energy input.