Effects of N-(4-azo-endo-tricyclo [5.2.1.0(2.6)]-decan-4-yl)-4-chloro-3-sulfamoylbenzamide (E 614; tripamide) on ganglionic transmission in the superior cervical ganglion of the guinea-pig.

Effects of E 614 on ganglionic transmission in the superior cervical ganglion of the guinea-pig were investigated with an intracellular recording technique. E 614 (10(-6) - 10(-5) M) did not modify the membrane potential, but induced a transmission failure in the ganglion upon preganglionic nerve stimulation at high frequency (20-30 Hz) without affecting action potentials induced by direct stimulation of the soma membrane. E 614 suppressed the amplitude of e.p.s.ps evoked by preganglionic nerve stimulation. Frequency and amplitude of miniature e.p.s.ps were also decreased in the presence of E 614. The results suggest that E 614 may act on preganglionic nerve terminals to suppress the release of transmitter during the activations of the nerve terminal by repetitive stimulation at high frequency. The agent may depress excess sympathetic activity without much affecting normal ganglionic transmission.