METABOLISM OF NAPHTHENIC HYDROCARBONS - UTILIZATION OF A MONOCYCLIC PARAFFIN, DODECYLCYCLOHEXANE, BY RAT

3H-Dodecylcyclohexane was incorporated in rat diet in order to study the metabolic utilization by mammals of a monocycloparaffin chosen as a typical naphthenic constituent of mineral oils. Dodecylcyclohexane was largely absorbed. No elimination of the hydrocabon was observed in urine while an extended excretion of3H occurred via this route. About 7% of absorbed dodecylcyclohexane was stored in the carcass, while the rest was ω-oxidized to cyclohexyldodecanoic acid, which incorporated into neutral lipids and phospholipids. The aliphatic chain of this unusual fatty acid underwent the normal fatty acid degradation pathways, leading to even fatty acids, squalene, cholesterol and nonlipid resynthesis, while the cyclohexyl ring was eliminated as urinary metabolites. Incorporation of ω-cyclohexyl fatty acids in phospholipids may raise a point of toxicological significance which is to be investigated. © 1979 American Oil Chemists' Society.