Effects of prenatal exposure to delta-9-tetrahydrocannabinol on reproductive, endocrine and immune parameters of male and female rat offspring

The effects of prenatal THC administration, given during the third week of gestation in rats, on the reproductive, endocrine and immune systems of the adult offspring were examined. THC treatment blocked the surge of testosterone which occurs in the male rat fetus on gestation day 18. Moreover, when copulatory parameters were measured in adult male offspring, males that had been exposed to THC in utero exhibited an increased latency to mount (THC: 245 +/- 49 vs vehicle: 99 +/- 12 sec) and none of the males ejaculated. Female rats exposed to THC in utero, exhibited an increased incidence of irregular estrous cycles and the number of females exhibiting lordosis behavior was reduced when compared to vehicle controls. Hormone analyses revealed that prolactin levels were significantly lower in the THC- vs vehicle-exposed male (THC: 5.2 +/- 0.4 vs vehicle: 0.4 +/- 0.6 ng/ml) and female offspring (THC: 5.7 +/- 0.3 vs vehicle: 12.2 +/- 1.8 ng/ml). However, there were no significant differences in basal plasma LH levels or in testicular weights of the male offspring. Thymus weight and total number of thymocytes were significantly higher in THC-exposed male and female rats when compared to vehicle controls. Together, these results indicate that maternal THC exposure has long-lasting effects on reproductive, endocrine and immune parameters of both male and female rat offspring.