Studies of Spontaneous Recovery of Central Respiratory Function after Acetylcholinesterase Inhibition by Organophosphates.
Technical rept. Jan 71-Jan 72,
EDGEWOOD ARSENAL MD
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Spontaneous recovery of the central respiratory function was studied in anesthetized guinea pigs intoxicated with either pinacolyl methylphosphonofluoridate Soman or isopropyl methylphosphonofluoridate Sarin. The animals were pretreated with atropine methylnitrate to protect muscarinic sites outside of the central nervous system. The intravenous administration of either Soman 38 micro gkg or Sarin 80 micro gkg produced an immediate disruption of phrenic nerve activity and resulting ventilatory failure. Animals were maintained on artificial respiration until spontaneous functional recovery was complete, as evidenced by the reestablishment of the synchronized burst of activity in the phrenic nerve and the return to tracheal airflow. This usually occurred within 1 hour. To determine whether the spontaneous recovery of respiration and the return of brainstem acetylcholinesterase AChE activity could be correlated, animals were sacrificed at predetermined intervals after intoxication, and the brainstem homogenates were analyzed for AChE activity. Results showed no significant return of AChE activity after 1 hour, although functional recovery of respiration was complete within this time. Author Modified Abstract