RELATION BETWEEN SCHEDULES OF EXPOSURE TO HEXANE AND PLASMA-LEVELS OF 2,5-HEXANEDIONE

  • 1 January 1982
    • journal article
    • research article
    • Vol. 4  (1) , 87-91
Abstract
Male Fischer rats were exposed repeatedly to high concentrations of hexane for 10 min in a pattern resembling human solvent abuse or to low concentrations of hexane continuously for 8 or 24 h daily. Concentrations of hexane in blood and brain were linearly related to the concentrations of hexane in the chamber after a 10-min exposure and declined thereafter, with half-lives of .apprx. 2.5 and 4 min in blood and brain, respectively. Despite the rapid elimination of hexane, neurotoxic levels of 2,5-hexanedione (2,5-HD) were formed from repeated 10-min exposures to a high concentration of hexane when the interexposure interval was 20 min. Neurotoxic levels of 2,5-HD also resulted from continuous exposure to much lower concentrations of hexane. Both exposure schedules caused an increase in 2,5-HD concentrations in blood after repeated daily treatments, suggesting induction of liver microsomal enzymes synthesizing 2,5-HD from hexane. The minimal sustained plasma 2,5-HD concentration that will result in neurotoxicity was < 50 .mu.g/ml in the rat.