[The role of the sympathoadrenal system in the development of acute muscle fatigue].

A substantial decrease in the sympathoadrenal system catecholamines was found to be the case in muscular fatigue (the animals were running on a treadmill to refusal), as evidenced by experimental studies on white rats. Sympatholytics bring about marked reduction in the catecholamine content in hypothalamus, cerebral hemispheres and the heart, which fact contributes to the development of muscular fatigue. That this is really the case is indicated by a substantial shortening of time during which the animals were running until they came to be at the end of their tether subsequent upon administration of raucedil (2.5 mg/kg), (from 2 h 58 min. to 12 min). Fatigue was found out to be manifest as a result of the sympathoadrenal system reserves depletion.