Effects of neonatal sympathectomy with antiserum to nerve growth factor or 6-hydroxydopamine on the acetylcholine sensitivity of the rat left atria were investigated. Sensitivities to acetylcholine of atria from immunologically and chemically sympathectomized rats were much higher than that of control at 4 weeks of age. These results suggest possible involvement of the sympathetic nervous system in regulation of cardiac cholinergic sensitivity.
