The fate of toluene and its metabolites in mice organs after ingestion of (14)C-toluene

Mice ingested (14)C-toluene orally, and the redioactivities of toluene and its metabolites in the blood, organs, urine, feces and exhaled air were determinated using liqid scintillation counter. Toluene absorbed from the digestive tract after 8 hours was caluculated by the ratio of subtracted amounts in digestive organs and feces from ingested toluene to ingested toluene was 98.92% and the ratio of amounts in mice excepting digestive organs, expired air and urine to ingested toluene was 92.09%. The ratio of toluene in expired air to ingested toluene after 8 hours was 31.15%, and of toluene as urinary metabolites was 16.64%. The concentration of toluene in the blood attained its maximum 60 minutes after ingestion and decreased with a half-life of 95 minutes. Concentration of toluene metabolites in the blood attained its maximun 120 minutes after ingestion and decreased with a half-life of 155 minutes. Amount of toluene in the exhaled air attained its maximum 60-75 minutes after ingestion and decreased with a 48 minute half-life. The concentration of toluene in blood and organs 180 minutes after ingestion was, in decreasing order, adipose tissue, kidneys, liver, cerebrum, and blood and concentration of toluene metabolites was, in decreasing order, kidneys, liver, blood, cerebrum and adipose tissue. Metabolites in blood and kidneys were identified as benzoic acid and hippuric acid, respectively. The metabolites in the liver was solely benzoic acid.