Increased VO2 max with right-shifted Hb-O2 dissociation curve at a constant O2 delivery in dog muscle in situ.
Increased VO2 max with right-shifted Hb-O2 dissociation curve at a constant O2 delivery in dog muscle in situ.
复制标题
在狗肌肉原位恒定输送 O2 的情况下，最大摄氧量增加，Hb-O2 解离曲线右移。
DOI：
10.1152/jappl.1998.84.3.995
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Wagner,PD
中科院分区：
文献类型：
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作者：
Richardson,RS;Tagore,K;Haseler,LJ;Jordan,M;Wagner,PD
如果肌肉中氧气输送的扩散成分对于决定运动能力很重要，那么毛细血管与组织差异的增加应该会增强运动过程中从血液到骨骼肌的气体交换。因此，O2 解离曲线向右移动理论上应该会增加 O2 提取并提高最大 O2 摄取（V˙o2 max）。为了检验这一假设，我们使用犬腓肠肌来研究 8 只狗在正常 P50（33.1 ± 0.4 Torr）下的最大运动量，并且 O2 解离曲线通过血红蛋白 (Hb) 变构调节剂（甲基丙酸，RSR-13；P50= 53.2 ± 5.0 Torr）向右移动。还在输注媒介物之前和之后对四只对照狗进行了研究。在运动过程中吸入 O2(100%)，以在两种情况下维持动脉饱和度。通过手术隔离肌肉并进行电刺激（强直训练：50 Hz 下 0.2 毫秒的刺激，持续 200 毫秒，每秒一次）。为了维持 O2 输送（RSR-13 前 = 19.1 ± 2.9；RSR-13 = 19.6 ± 2.5 ml ⋅ 100 g−1⋅ min−1），对肌肉进行泵灌注。在恒定的 O2 输送量下，RSR-13 显着增加了 O2 提取百分比（RSR-13 前 = 61 ± 4.0；RSR-13 = 75.5 ± 4.7）和肌肉 V˙o2 max（RSR-13 前 = 11.8 ± 2.1；RSR-13 = 14.2 ± 1.5 ml ⋅ 100 g−1⋅ min−1）。随着 P50 的增加，最大摄氧量 (V˙o2 max) 的改善表明了当 P50 正常时其对 O2 供应的依赖性，以及最大运动时 O2 扩散输送至肌肉的重要性。
If the diffusive component of O2transport in muscle is important in determining exercise capacity, an increased capillary-to-tissuedifference should enhance gas exchange from blood to skeletal muscle during exercise. Thus a rightward shift in the O2dissociation curve should theoretically increase O2extraction and improve maximal O2uptake (V˙o2 max). To test this hypothesis, we used the canine gastrocnemius muscle to study maximal exercise in eight dogs at a normal P50(33.1 ± 0.4 Torr) and with the O2dissociation curve shifted to the right by an allosteric modifier of hemoglobin (Hb) (methylpropionic acid, RSR-13; P50= 53.2 ± 5.0 Torr). Four control dogs were also studied before and after infusion of vehicle. O2(100%) was inspired during exercise to maintain arterial saturation in both conditions. The muscle was surgically isolated and electrically stimulated (tetanic train: 0.2-ms stimuli for 200-ms duration at 50 Hz, once per s). To maintain O2delivery (pre-RSR-13 = 19.1 ± 2.9; RSR-13 = 19.6 ± 2.5 ml ⋅ 100 g−1⋅ min−1), the muscle was pump perfused. At a constant O2delivery, RSR-13 significantly increased percent O2extraction (pre-RSR-13 = 61 ± 4.0; RSR-13 = 75.5 ± 4.7) and muscle V˙o2 max(pre-RSR-13 = 11.8 ± 2.1; RSR-13 = 14.2 ± 1.5 ml ⋅ 100 g−1⋅ min−1). This improvement inV˙o2 maxwith increased P50demonstrates its O2supply dependence when P50is normal and the importance of O2diffusive transport to muscle at maximal exercise.