Excretion of triethyl lead, diethyl lead and inorganic lead after injection of tetraethyl lead in rabbits (author's transl)

Abstract

Rabbits were dosed with tetraethyl lead at 12 mg/kg; their organs, bloods, urines and feces were then assayed for tetraehyl lead, triethyl lead, diethyl lead, inorganic lead and total lead, and the chemical species of the lead excreted in the urines and feces were also studied. 1) One day after the dosing, the total lead in the urine was made up of about 69% diethyl lead, about 27% inorganic lead and about 4% triethyl lead. This ratio of the chemical species of lead to total lead remained unchanged even 7 days after the dosing. 2) Two days after the dosing, the total lead in the feces consisted of about 85% inorganic lead, about 9% diethyl lead and about 6% triethyl lead. Seven days after the dosing, the total lead in the feces comprised about 95% inorganic lead, about 4% triethyl lead and about 1% diethyl lead. 3) Intravisceral levels of lead were also measured 24 hours after the dosing. Triethyl lead accounted for about 84% of the total lead in the liver, about 68% in the kidneys, and about 59% in the blood. 4) Lead levels in B bile and intestinal contents were determined 24 hours after the dosing. Diethyl lead accounted for about 93% of total lead in B bile, while inorganic lead made up about 90% of the total lead in the cecal, the colonic and the rectal contents. 5) Conversion of diethyl lead by intestinal contents was studied in vitro by adding diethyl lead to the intestinal contents of normal rabbits. Incubation of the mixtures in the presence of N2 at 38°C for 180 minutes resulted in the conversion of 16% of the diethyl lead into inorganic lead in the cecal, the colonic and the rectal contents. The conversion of diethyl lead into inorganic lead in the cencal contents was followed up and it was found that the inorganic lead output increased with the passage of time. Diethyl lead proved to be the principal chemical species of lead that is eliminated into the urine and bile after dosing rabbits with tetraethyl lead. However, inorganic lead accounted for the major portion of the lead excreted into the feces. This finding suggested that the diethyl lead eliminated into the bile could be converted into inorganic lead in the intestines.