SOME EFFECTS OF DHSOPROPYL FLUOROPHOSPHATE (DFP) AND FLUOROACETATE ON THE CENTRAL NERVOUS SYSTEM

Abstract

Attempts were made to produce convulsions in cats by intracarotid and intracisternal injections of diisopropyl fluorophosphate (DFP). No convulsions were obtained in either instance. Systemic symptoms appeared, however, and plasma cholinesterase was sharply reduced. Intracarotid DFP produced prolonged ipsilateral myosis and salivation. E.E.G. changes on the side of the injection were found in one of two trials. Intracisternal DFP caused prolongation (threefold) of the pentothal anesthesia. The animals, upon awakening, showed a temporary loss of sensation in the forelimbs and cornea with weakness of the hind limbs and a waddling gait. Intracisternal fluoroacetate produced curious generalized seizures. These were classified as scissors spasms, scratching seizures, and myoclonic jerks. They appeared after about three-quarters of an hour, in contrast to the latent period of two to three hours after intravenous injection. Seizures persisted for hours unless stopped with nembutal. Cerebrospinal fluid (CSF) was tested for acetylcholine (ACh), the minimum amount detectable during our experiments being 0.4 to 3.0 μgm. %. After intravenous injections of 1.5 mgm. per kgm. of DFP preceding convulsions produced by thujone, small amounts of ACh appeared in three out of four experiments. Intravenous injection of 5.0 mgm. per kgm. of DFP resulted in 3.0 μgm. % of ACh in the CSF. No ACh was found after the other procedures described.