Chlorinated paraffins: formation of sulphur-containing metabolites of polychlorohexadecane in rats

Abstract

1. A uniformly ¹⁴C-labelled polychlorinated hexadecane (¹⁴C-PCHD; 65% chlorine by wt) was injected into the portal vein in bile duct-cannulated rats (5–6 mg/kg) and the bile was collected for two or three days.

2. Less than 3% of the total amount of radioactivity excreted in the bile was due to unchanged ¹⁴C-PCHD. The radioactivity was separated by ion-exchange chromatography into two major fractions: one acidic, the other amphoteric. Comparison with a similar fractionation of propachlor metabolites indicates that the fractions contain ¹⁴C-PCHD conjugates of N-acetylcysteine (mercapturic acid) and glutathione, respectively.

3. The tentative ¹⁴C-PCHD-mercapturic acid on t.l.c. had an R_F value similar to that of a synthetic PCHD-mercapturic acid, and chlorine and divalent sulphur were shown to be present.

Key Words:

• Bile
• 1-chloro-polychloro-[U-¹⁴C]hexadecane
• ion-exchange chromatography
• liquid-gel extraction
• mercapturic acid pathway
• rat