Distribution and elimination of 14C-hexachlorobenzene after single oral exposure in the male rat.

The distribution and excretion of 14C-hexachlorobenzene (14C-HCB) after administration to rats of a single oral dose of 50 microCi 14C-HCB per kg body weight was studied by whole-body autoradiography and liquid scintillation counting. Radiolabelled HCB was distributed throughout the body in 2 hours. Peak levels were found at 4 hours in the liver and the brown fat and at 24 hours in the abdominal and subcutaneous fat. The highest concentrations were found in the adipose tissues, the bone marrow, the skin, the Harderian gland, the nasal mucosa, the praeputial gland, and the intestinal tract. After 90 days, substantial amounts were present only in the adipose tissue, the skin, the nasal mucosa, and the praeputial gland. Part of the radioactivity in the brown fat, the bone marrow, the praeputial gland, the adrenal gland, the liver, the blood, the kidney, the spleen, the lungs, the heart and the gastrointestinal contents was found not to be evaporable on sections heated to 50 degrees for 24 hrs and was considered to represent metabolites of HCB. Some radioactivity remained in the liver, the kidney, the heart and the intestinal contents after evaporation and extraction of the sections with polar and nonpolar solvents and was supposed to reflect metabolites of HCB associated to tissue macromolecules. Besides urine and faeces, the results indicated the following excretory pathways: Intestinal mucosa, sebacous glands, nasal mucosa and the praeputial and Harderian gland.