Reappraisal of diffusion, solubility, and consumption of oxygen in frog skeletal muscle, with applications to muscle energy balance.
Reappraisal of diffusion, solubility, and consumption of oxygen in frog skeletal muscle, with applications to muscle energy balance.
复制标题
在青蛙骨骼肌中重新评估扩散，溶解度和氧气消耗，并应用于肌肉能量平衡。
DOI：
10.1085/jgp.86.1.105
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发表时间：
1985-07
影响因子：
3.8
通讯作者：
Peskoff, A
中科院分区：
文献类型：
--
作者：
Mahler, M;Louy, C;Homsher, E;Peskoff, A
之前我们测试了青蛙切除缝匠肌中 O2 一维扩散方程的有效性，并用它来测量该肌肉中 O2 的扩散系数 (D) 以及破伤风后 O2 消耗率 (Qo2) 的时间过程 (Mahler, 1978, 1979, J. Gen. Physiol., 71:533-557, 559-580, 73:159-174）。事实上，青蛙缝匠肌的横截面与宽度除以最大厚度平均为 5.1 +/- 0.2 的半椭圆形非常吻合。将先前的技术与二维扩散方程和此半椭圆边界结合使用，产生的 D 值比先前报告的值小 30%； 0、10 和 22.8 摄氏度下的修正值分别为 6.2、7.9 和 10.8 X 10(-6) cm2/s。 20℃破伤风后，Qo2迅速上升至峰值，然后呈指数下降，时间常数（tau）比之前报道的快大约15%； tau 在林蛙 (Rana temporaria) 中的平均时间为 2.1 分钟，在林蛙 (Rana pipiens) 中的平均时间为 2.6 分钟。设计了一种技术来测量 O2 在完整的呼吸肌肉中的溶解度 (α)，并得出 α（肌肉）/α (H2O) = 1.26 +/- 0.04。通过这些修改，用扩散法获得的 O2 消耗值与用 Kushmerick 和 Paul 的直接法测量的值一致(1976，J.Physiol.[Lond.].，254：693-709)。使用这两种方法的结果，在 20 摄氏度下，破伤风期间磷酸肌酸分裂与恢复期间 O2 消耗的比率范围为 5.2 至 6.2 mumol/mumol，收缩后 ATP 水解估计为 13.6 +/- 4.1 (n = 3) nmol/mumol 总肌酸。
Previously we tested the validity of the one-dimensional diffusion equation for O2 in the excised frog sartorius muscle and used it to measure the diffusion coefficient (D) for O2 in this muscle and the time course of its rate of O2 consumption (Qo2) after a tetanus (Mahler, 1978, 1979, J. Gen. Physiol., 71:533-557, 559-580, 73:159- 174). A transverse section of the frog sartorius is in fact well fit by a hemi-ellipse with width divided by maximum thickness averaging 5.1 +/- 0.2. Using the previous techniques with the two-dimensional diffusion equation and this hemi-elliptical boundary yields a value for D that is 30% smaller than reported previously; the revised values at 0, 10, and 22.8 degrees C are 6.2, 7.9, and 10.8 X 10(-6) cm2/s, respectively. After a tetanus at 20 degrees C, Qo2 rose quickly to a peak and then declined exponentially, with a time constant (tau) approximately 15% faster than that reported previously; tau averaged 2.1 min in Rana temporaria and 2.6 min in Rana pipiens. A technique was devised to measure the solubility (alpha) of O2 in intact, respiring muscles, and yielded alpha (muscle)/alpha (H2O) = 1.26 +/- 0.04. With these modifications, the values for O2 consumption obtained with the diffusion method were in agreement with those measured by the direct method of Kushmerick and Paul (1976, J. Physiol. [Lond.]., 254:693- 709). Using results from both methods, at 20 degrees C the ratio of phosphorylcreatine split during a tetanus to O2 consumption during recovery ranged from 5.2 to 6.2 mumol/mumol, and postcontractile ATP hydrolysis was estimated to be 13.6 +/- 4.1 (n = 3) nmol/mumol total creatine.