Effects of epinephrine and lactate on the increase in oxygen consumption of nonexercising skeletal muscle after aerobic exercise

The purpose of this study was to measure O-2 consumption of nonexercising skeletal muscles (V) over dotO(2nonex)) at rest and after aerobic exercise and to investigate the stimulant factors of O-2 consumption. In experiment 1, we measured the resting metabolic rate of the finger flexor muscles in seven healthy males by P-31-magnetic resonance spectroscopy during a 15 min arterial occlusion. In experiment 2, the (V) over dotO(2nonex) of the finger flexor muscles was measured using near infrared continuous wave spectroscopy at rest, immediate postexercise, and 3, 5, 10, 15, and 20 min following a cycling exercise at a workload corresponding to 50% of peak pulmonary O-2 uptake for 20 min. We also monitored deep tissue temperature in the (V) over dot O-2nonex measurement area and determined catecholamines and lactate concentrations in the blood at rest and immediate postexercise. (V) over dotO(2nonex) at rest was 1.1 +/- 0.1 muM O-2/s (mean+/-standard error) and (V) over dotO(2nonex) after exercise increased 59.6+/-7.2% (p<0.001) from the resting values. There were significant correlations between the increase in (V) over dot O-2nonex and the increase in epinephrine concentration (p<0.01), and between the increase in (V) over dotO(2nonex) and the increase in lactate concentration (p <0.05). These results suggest that epinephrine and lactate concentrations are important (V) over dotO(2nonex) stimulant factors. (C) 2000 Society or Photo-Optical Instrumentation Engineers. [S1083-3668(00)00304-X].