Excretion of tetramethyllead, trimethyllead, dimethyllead and inorganic lead after injection of tetramethyllead to rabbits.

Rabbits were divided to groups of 3, and injected either 9.9 mg of tetramethyllead (Me4Pb)/kg of body weight (7.7 mg Pb/kg) or 39.7 mg/kg (30.8 mg Pb/kg) into the ear vein once only, respectively, and urinary and fecal excretions of lead were studied for chemical species and total lead during the following 7 days. In the group injected 9.9 mg/kg, the urinary total lead excretion was composed of about 73% dimethyllead (Me2Pb2+), about 19% trimethyllead (Me3Pb+), about 6% inorganic lead (Pb2+), and about 2% Me4Pb on the day following the injection, and 100% Me3Pb+ 7 days after the injection. In the group injected 39.7 mg/kg, the urinary total lead excretion was composed of about 67% Me2Pb2+, about 14% Me3Pb+, about 17% Pb2+, and about 2% Me4Pb on the day following the injection, and about 8% Me2Pb2+, about 74% Me3Pb+, about 17% Pb2+, and about 1% Me4Pb 7 days after the injection. In both groups, the fecal total lead excretion during 7 days after the injection was entirely composed of Pb2+. During the 7 days, 1-3% of either administered dose was excreted in the urine, and 7-19% in the feces. The urinary total lead excretion in the rabbits injected Me4Pb was similar to that in the rabbits injected tetraethyllead, but the fecal total lead excretion in the former was extremely smaller. This extremely small fecal excretion of total lead appeared to have resulted from the less elimination of lead into the bile of Me4Pb-injected rabbits.