Characteristics of Neuronal Effects of DDT and Dieldrin in Mice

Abstract

Neurotoxic effects of clofenotane (DDT) and dieldrin were analyzed pharmacologically in mice. Oral (p. o.) or intravenous (i. v.) administration of DDT caused the tremor, while dieldrin caused the tonic or clonic convulsion. Intracerebroventricular (i. c. v.) injection of both agents also caused the neurotoxic symptoms which were qualitatively similar to those shown after p. o. or i. v. administration. These effects may be central nervous system in origin since i. v. injection of either insecticides had no direct effect on sciatic nerve-gastrocnemius muscle system after the nerve had been sectioned. The tremor due to DDT was aggravated by dopaminergic antagonist but unaffected by muscarinic antagonist. The convulsion due to dieldrin was alleviated by muscarinic or dopaminergic antagonist but aggravated by adrenergic or GABA ergic antagonist. These differences suggest that DDT and dieldrin develop their neurotoxic symptoms through different neural pathway(s).