Acute experiments on rats were performed to study the influence of water-soluble chemical carcinogens on synaptic transmission via the inferior mesenteric sympathetic ganglion. Synaptic transmission was studied before and after intravenous injection of the enterotropic carcinogen 1,2-dimethylhydrazine (DMH) and N-nitrosomethylurea (NMU) which induces the development of mammary gland tumors. Despite the different chemical structure and specificity of the action of the carcinogens used on one or another target tissue, their influence on synaptic transmission via the sympathetic ganglia was of identical character, manifested by the blocking action on transmission of nerve impulses. Comparison of the action of DMH and NMU on synaptic transmission with the influence of some other pharmacological substances suggests that the mechanism of the inhibitory action of the carcinogens on synaptic transmission via the sympathetic ganglia may be linked both with cholinolytic and adrenomimetic influences of the carcinogens.
Action Potentials Animals