The effect of trichloroethylene on male sexual behavior: possible opioid role.

Trichloroethylene (TCE) is a chlorinated hydrocarbon solvent which is widely used as an industrial degreasing agent. Workers exposed to TCE often exhibit symptoms similar to those symptoms produced by narcotics. The present studies evaluated the effects of TCE exposure on measures of male sexual behavior in rats. The data indicated that TCE (1000 mg/kg, PO) 4 hours before testing produced an increased ejaculation latency effect on male copulatory behavior. Naltrexone (2.0 mg/kg, IP) given 15 minutes before testing blocked this TCE-induced effect. Animals given chronic TCE administration showed tolerance to TCE's effect by the end of two weeks. Cross-tolerance to morphine was also demonstrated at this time. Quaternary naloxone failed to block any of the TCE-induced effects. These data suggest that many of TCE's effects may be mediated via the endogenous opioid system at a CNS level.