SIMULTANEOUS IN-VIVO MEASUREMENTS OF HBO(2) SATURATION AND PCR KINETICS AFTER EXERCISE IN NORMAL HUMANS
SIMULTANEOUS IN-VIVO MEASUREMENTS OF HBO(2) SATURATION AND PCR KINETICS AFTER EXERCISE IN NORMAL HUMANS
复制标题
DOI：
10.1152/jappl.1994.77.1.5
复制
发表时间：
1994-07-01
影响因子：
3.3
通讯作者：
CHANCE, B
中科院分区：
文献类型：
--
作者：
MCCULLY, KK;IOTTI, S;CHANCE, B
同时测定了5名男性受试者小腿肌肉在运动后恢复过程中的磷酸肌酸(PCr)和氧合血红蛋白(HBO(2))饱和度。用磁共振波谱技术测量了2.0-T 78厘米口径磁体和9厘米直径表面线圈的聚合酶链式反应。利用近红外光谱测量相对HBO(2)饱和度，即750 nm和850 nm光的吸收差值。光源和探测器的距离为3 cm。运动包括仰卧位等速足底屈曲。执行两个5min的次极量方案，将PCR耗尽到静止值的60%，pH值为>；7.0。然后进行两次1min的快速足底屈曲，使PCR值降至静止值的5-20%，pH值为6.8。聚合酶链式反应峰面积(每8个S)和高压氧(2)饱和面积(每1个S)符合单指数函数，并计算出时间常数。极量运动后的聚合酶链式反应时间常数(68.3+/-10.5 S)大于次极量运动后的聚合酶链式反应时间常数(36.0+/-6.5 S)，这与低pH对聚合酶链式反应恢复的影响是一致的。HBO(2)复氧接近次极量PCr恢复，极量运动(29.4+/-5.5 S)和次极量运动(27.6+/-6.0 S)之间差异无统计学意义。我们的结论是，只要肌肉的pH值保持在7.0附近，聚合酶链式反应回收率的磁共振光谱测量和HBO(2)饱和度恢复的近红外光谱测量提供了类似的信息。
Simultaneous measurements of phosphocreatine (PCr) and oxyhemoglobin (HbO(2)) saturation were made during recovery from exercise in calf muscles of five male subjects. PCr was measured using magnetic resonance spectroscopy in a 2.0-T 78-cm-bore magnet with a 9-cm-diam surface coil. Relative HbO(2) saturation was measured as the difference in absorption of 750- and 850-nm light with use of near-infrared spectroscopy. The light source and detectors were 3 cm apart. Exercise consisted of isokinetic plantar flexion in a supine position. Two 5-min submaximal protocols were performed with PCr depletion to 60% of resting values and with pH values of > 7.0. Then two 1-min protocols of rapid plantar flexion were performed to deplete PCr values to 5-20% of resting values with pH values of < 6.8. Areas of PCr peaks (every 8 s) and HbO(2) saturation (every 1 s) were fit to a monoexponential function, and a time constant was calculated. The PCr time constant was larger after maximal exercise (68.3 +/- 10.5 s) than after submaximal exercise (36.0 +/- 6.5 s), which is consistent with the effects of low pH on PCr recovery. HbO(2) resaturation approximated submaximal PCr recovery and was not different between maximal (29.4 +/- 5.5 s) and submaximal (27.6 +/- 6.0 s) exercise. We conclude that magnetic resonance spectroscopy measurements of PCr recovery and near-infrared spectroscopy measurements of recovery of HbO(2) saturation provide similar information as long as muscle pH remains near 7.0.