大鼠骨骼肌在体状态下的质子外流：高血压状态下的变化

Proton efflux from rat skeletal muscle in vivo: changes in hypertension.

Kemp G J, Thompson C H, Radda G K

MRC Biochemical and Clinical Magnetic Resonance Unit, John Radcliffe Hospital, Oxford, U.K.

Clin Sci (Lond). 1992 May;82(5):489-91. doi: 10.1042/cs0820489.

Abstract

An analysis of the recovery kinetics of intracellular pH and phosphocreatine concentration after exercise in skeletal muscle was developed to calculate the rate of proton efflux in vivo. 2. Recovery of rat leg muscle pH after sciatic nerve stimulation was faster in spontaneously hypertensive rats than in Wistar-Kyoto controls (both n = 5). 3. Analysis of these data showed that the rate of proton efflux depends on intracellular pH, being greater at lower pH. 4. The early rate of proton efflux was greater in spontaneously hypertensive rats [measured over the first 0.8 min, 12.5 mmol min-1 kg-1 (SEM 1.8) in spontaneously hypertensive rats compared with 7.6 mmol min-1 kg-1 (SEM 0.4) in Wistar-Kyoto rats, P less than 0.05], even though pH at the start of recovery was higher [6.30 (SEM 0.03) in spontaneously hypertensive rats compared with 6.17 (SEM 0.01) in Wistar-Kyoto rats, P less than 0.01]. 5. This novel analysis provides a quantitative estimate of the rate of proton efflux in vivo, and demonstrates directly that this is increased in spontaneously hypertensive rats, as has previously been inferred from pH changes during exercise and studies of cultured muscle cells in vitro.

摘要

为了计算体内质子流出速率，开展了一项对骨骼肌运动后细胞内pH值和磷酸肌酸浓度恢复动力学的分析。2. 坐骨神经刺激后，自发性高血压大鼠腿部肌肉pH值的恢复比Wistar-Kyoto对照大鼠更快（n均为5）。3. 对这些数据的分析表明，质子流出速率取决于细胞内pH值，在较低pH值时更大。4. 自发性高血压大鼠早期质子流出速率更高[在最初0.8分钟内测量，自发性高血压大鼠为12.5 mmol·min⁻¹·kg⁻¹（标准误1.8），而Wistar-Kyoto大鼠为7.6 mmol·min⁻¹·kg⁻¹（标准误0.4），P<0.05]，尽管恢复开始时的pH值更高[自发性高血压大鼠为6.30（标准误0.03），Wistar-Kyoto大鼠为6.17（标准误0.01），P<0.01]。5. 这项新的分析提供了体内质子流出速率的定量估计，并直接证明自发性高血压大鼠的质子流出速率增加，正如先前从运动期间的pH值变化和体外培养肌肉细胞的研究中所推断的那样。