The role of testosterone in trichloroethylene penetration in vitro.

Sex differences are known to exist in the metabolism and bioavailability of trichloroethylene (TCE). This study revealed that dermal penetration of [14C]TCE in vitro was twofold greater in untreated female than in untreated male Sprague-Dawley rats. Since testosterone has been shown to mediate a wide variety of sex differences, its role in dermal penetration of [14C]TCE was investigated. Penetration was measured by using an in vitro evaporation-penetration cell with a 10-hr collection period. Depriving male rats of testosterone (by castration) resulted in increased values for total penetration, area under the curve (AUC), and penetration slopes compared to those for male control animals. The values for male animals deprived of testosterone approached those found in the female control group. Administration of testosterone to female animals produced values for total penetration, AUC, and penetration slopes significantly lower than those of the female control group.