Enhancement by desipramine of hypothalamically evoked discharges in preganglionic sympathetic nerves

Desipramine in intravenous doses of 0.3 to 3 mg/kg in the cat enhances preganglionic cervical sympathetic nerve activity evoked by hypothalamic stimulation. This effect is dependent on the pulse frequency of stimulation. Spontaneous potentials are in general slightly diminished. Reflex excitation of preganglionic sympathetic outflow induced by sciatic nerve stimulation is not altered by desipramine. The described effects are interpreted as the result of a modulating influence of desipramine on central structures controlling sympathetic outflow.