Further studies on the toxicity of some tetra and trialkyl lead compounds.

The toxicity of tetra and trimethyl and propyl lead compounds has been studied after their administration to rats and rabbits. The toxicity to rats of tetramethyl lead has been compared with tetraethyl lead when given by inhalation. Both tetramethyl and tetrapropyl lead were found to be considerably less toxic than trimethyl and tripropyl lead. There was evidence of a slow rate of conversion of the tetra to the trialkyl lead forms in rats in vivo. Although there was a distinct difference between the signs of poisoning seen after giving the methyl or the propyl lead compounds the primary site of action for both groups appeared to be the central nervous system. Some biochemical studies using slices of rat brain cortex showed that trimethyl and tripropyl lead inhibited the oxidation of glucose whereas tetramethyl and tetrapropyl lead were a hundred times less active in this respect.