[Increase in the contractile force of the skeletal muscles during the reflex activation of the sympathetic nervous system].

In anesthetized cats, the muscles of hindlimb if contracting in steady-state regimen (one brief tetanic contraction every 5 sec) under direct stimulation with trains of electrical pulses increase their contraction force following a sudden decrease of arterial blood pressure (down to 60 mm Hg) or asphyxia. This reflex reaction reaches its maximum (the increase in the force by 38.2 +/- 6.6%) if the muscle contracts with 25% of the maximal force. The sympathetic nerve influence is transduced through beta adrenoreceptors.