The experimental study on the neurotoxic action of phthalodinitrile

Abstract

The toxic action of phthalodinitrile (abbr, P D N) on the nervous system was investigated by the electrophysiological method in rabbits.
1. The neuro-physiological investigation of the cramp attack caused by P D N and its neurotoxic action.
2. The effect of the repeated administration of P D N by the inplanted electrode method.
3. The effect of anti-convulsants on the cramp attack caused by P D N.
4. The patho-histological investigation of the toxic action of P D N.
5. The summary and consideration of the experimental investigations.
The results obtained are as follows:
1) Clonic cramp attacks of the whole body were always observed when over 25mg/kg of P D N was administered intraperitoneally and also sometimes when 10-20 mg/kg of P D N was administered.
The repeated administration of, a small dose caused cramp attack, and a single administration of the dose did not cause it.
2) An administration of P D N acted inhibitorily on the arousal reaction in the E E G caused by the electro-stimulus in the thalamus and midbrain reticulum formation an d acted acceleratively on the simultaneously evoked muscle discharges.
3) The seizures were evoked in the E E G of neo-and archi-cortex after the administration of P D N to the rabbits of cerveau isole, however the cramp attacks of the whole body were not observed.
Anti-convulsants, that is, Acetazolamide, Dichlorphenamide, etc, depressed the seizure waves in the E E G caused by P D N.
It may be said that the hyper-kinetic effec t of P D N acts on the higher part of the brain.
4) In the cases of the acute experiments, the slow waves in the neo-cortex E E G preceded to the seizure waves; the ropeated administration of P D N 10mg/kg caused the slow-wave in the neo-cortex E E G.
It may be said that the slow waves caused by the administration of P D N are the premonitor of cramp attack.5) Pseudocerebral phagocytes, slight infiltration and atrophy of the cerebral cells were observed in the cases of the repeated administration of P D N for 60 days, but t here is no evidence of edema and inflammation.