THE PHARMACOLOGICAL PROPERTIES OF THE INSECTICIDE DIELDRIN

The effects of dieldrin (hexachloro-epoxy-octahydro-dimethanonaphthalene) were studied in acute experiments on cats and rabbits. When injected intravenously or intra-arterially, it caused excitation of the central nervous system, which resulted in increased reflex excitability, convulsions, bradycardia, and some vasodepression. Dieldrin potentiated the effects of acetylcholine on the central nervous system and on the circulatory system as well as on intestinal motility. These latter manifestations were abolished by section of the vagus nerves, indicating a central action. Dieldrin had no effect on salivary secretion produced either by stimulation of the chorda tympani or by injections of acetylcholine in the decentralized submaxillary gland. Thus, although dieldrin has a marked parasympathomimetic action, this effect is exerted through stimulation of central mechanisms and not peripherally.