Exposure to toluene and stress during pregnancy impairs pups' growth and dams' lactation.

Abstract Inhalant misuse starts at an early age, and a large number of users are women in reproductive age. This study investigates whether exposure to toluene, a commonly misused solvent, alone or combined with restraint stress during pregnancy, produces adverse effects in pregnant mice and their offspring during lactation and adulthood. Pregnant animals were exposed to either 8000 ppm toluene (30 min/twice daily from gestational days 7–19), restraint stress (three times/day during the same gestation period) or both; control mice were only exposed to air. Our results show that toluene, stress and their combination reduced body weight gain in pregnant females without changing food consumption. In the offspring, all treatments resulted in low body weight at weaning, but with the toluene and stress combination this effect was seen from birth. Weight deficiency could not be attributed to poor maternal behavior during the first 3 weeks of age, but to a reduction in pro-TRH mRNA expression in the hypothalamic paraventricular nucleus and serum prolactin levels in dams. After weaning, pups that were subjected to toluene and stress during gestation had lower body weight and ate less than control animals. In conclusion, the combined exposure to toluene and stress during pregnancy lead to more pronounced effects in dams and longer-lasting actions in pups than exposure to either toluene or stress.