Systemic administration of procaine suppresses the somato-sympathetic reflex discharges in anesthetized cats.

Somato-sympathetic reflex discharges (SSRDs) which were induced from the lumbar sympathetic truck elicited by train pulse stimulation of femoral nerves in anesthetized cats were examined during and after intravenous infusion of 1 mg.kg(-1).min(-1) of procaine. The infusion demonstrated that amplitudes were suppressed with prolonged latencies and/or their tendencies in A- and C-reflex potentials of SSRDs. Heart rate and blood pressure decreased slightly, and the decreases correlated with time courses of suppressed SSRDs. These results suggest that the systemic procaine infusion may be a reliable method to alleviate somato-sympathetic reflexes under such conditions as extreme stimulation of somatic afferent nerves observed in surgical procedures.