Ganglionic effect of beta adrenergic receptor blocking agents

When tested on the isolated sympathetic ganglion of the rat and frog, beta adrenergic blocking agents were found to inhibit synaptic transmission. This effect can be attributed, in some cases, to the aspecific membrane-stabilizing effect of the drugs, and in other instances to a specific ganglionic blocking property of the agents tested. Beta blockers proved to be more potent ganglioplegics than hexamethonium, their effect was in turn surpassed by pempidine and d-tubocurarine. In some cases the duration of the transmission block induced by beta blockers was longer than that of the reference compounds. On basis of the obtained results, it might not be excluded that the antihypertensive effect of beta adrenergic blocking agents involves a ganglionic component.