STUDIES ON THE THERAPEUTIC EFFECT OF 2-PYRIDINE ALDOXIME METHIODIDE (2-PAM) IN MAMMALS FOLLOWING ORGANOPHOSPHORUS COMPOUND-POISONING (REPORT III):DISTRIBUTION AND ANTIDOTAL EFFECT OF 2-PAM IN RATS

Abstract

The metabolic fate of 2-PAM and its antidotal effect on organophosphorus compound poisoning in rats were studied. When ¹⁴C-2-PAM was administered intravenously, the amount of ¹⁴C reaching the brain was small. Following administration by intramedullary injection, ¹⁴C was present in high concentrations in the brain, and 72-90% of the ¹⁴C present in the brain corresponded to the unchanged form of 2-PAM. 2-PAM was rapidly excreted into the urine and feces following either intramedullary or intravenous administration. The half-life of 2-PAM in the brain following intramedullary administration was 1.52 hr. Intramedullary administration of 2-PAM to rats poisoned with fenitrothion or malathion enabled their survival and induced reactivation of brain cholinesterase.