Effects of Transplacental Exposure of delta(sup 9)-Tetrahydrocannabinol in Rats

摘要

The major psychoactive ingredient of marihuana, delta (sup 9)-tetrahydrocannabinol (THC) was evaluated for its genetoxicity in the CD Sprague-Dawley rat using the transplacental intraperitoneal infusion sister chromatid exchange (SCE) assay. It was found that at 300 mg/kg body weight (b.w.) THC in dimethylsulfoxide (DMSO) induces SCE at all stages examined in the whole fetus and fetal liver, but not in the bone marrow of the mother. A significant response was also seen at 150 mg/kg b.w. but to a lesser degree consistent with a dose-dependent phenomenon. THC was found to be more genotoxic in early gestation than in late gestation, and induces more SCE in fetal liver than fetal brain. Organogenesis appears to be a period when the rat is extremely sensitive to the genotoxic action of THC.