Pyrenebutyl-methylphosphonofluoridate: A fluorescent anti-cholinesterase in vivo

Abstract

In vivo properties of pyrenebutyl-methylphosphonofluoridate (PBMPF) have been studied. The LD50 (i.v.) for mice was 15 mg/kg and toxic symptoms were typical of cholinesterase (ChE) inhibition but central signs were absent. After intraventricular injection of PBPMPF in unanaesthetized rabbits, continued walking in bizarre circular fashion together with peripheral vascular dilation and tachypnoea were observed. Recovery occurred 3 h post-injection. Fluorescent particles of anabsorbed material juxtaposed on lining ependyma were observed up to 14 days of administration. In addition, a large number of hippocampal cells showed vivid fluorescence, particularly in the cytoplasm, which was attributed to ChE inhibition. It is concluded that PBMPF seems promising as an organophosphate marker of nerve cells.