Toxicological considerations in the assessment of lead exposure.

: Groups of rats received single subcutaneous injections of the highly toxic organophosphate compound, soman, in doses of 106, 133 or 165 micrograms/kg and were observed during the acute phase of intoxication. Survivors were killed at intervals up to fourteen days after exposure, and brain sections were examined by light microscopy. A consistent pattern of neuronal degeneration and necrosis was observed in brains of animals which had experienced convulsions during the intoxication. The lesions had an appearance and distribution similar to that reported for both hypoxic injury and status epilepticus. No lesions were observed in animals which did not experience convulsions. The results indicate that soman, and possibly other similar organophosphate compounds, may produce significant irreversible damage to the central nervous system.