[Neurotropic action of chemical carcinogens]

The effect of 4-dimethylaminoazobenzole, 4-diethylaminoazobenzole, 1,2-dimethylhydrazine and N-nitrosomethylurea on the synaptic transmission of impulses through the inferior mesenteric sympathetic ganglion is investigated in acute experiments with rats. It is found that irrespective of chemical structure of carcinogens and different specificity of their action on the various tissues-targets all these carcinogens inhibit the cholinergic ganglionic transmission. The inhibitory action of carcinogens may be connected with the excitement of presynaptic alpha-adrenoreceptors in sympathetic ganglia. Pyrroxane, an alpha-adrenoblocker, protects the synaptic transmission from the action of carcinogens.