Correlation between respiratory reflex and acetylcholine content of pons and medulla

¹ Department of Physiology, Medical College of South Carolina, Charleston, South Carolina

Experiments indicate that there is a significant correlation between respiratory function (as measured by the reflex response to electrical stimulation of Hering's nerve) and the total acetylcholine (ACh) concentrations in the pons and medulla, after intravenous administration of the hemicholinium, HC-3 (,', dimethylethanolamino 4,4' biacetophenone), a drug which inhibits the synthesis of ACh. With a decreasing respiratory reflex response there is a corresponding progressive and gradual decrease in the total ACh content in the pons and medulla. These experiments lend additional support to the hypothesis of the participation of a cholinergic factor in central respiratory control, particularly in view of the fact that these investigations are in harmony with earlier studies in which other biochemical rearrangements were induced within the cholinergic system.