Objective To evaluate the effects of gestational exposure to nicotine on the levels of monoamine neurotransmitters in various brain regions of rat offspring.

Methods Twenty-four pregnant SD rats were randomly divided into four groups and treated with nicotine saline at dose of 0.0, 1.0, 2.0, and 4.0 mg/kg daily through subcutaneous injection starting from the seventh gestational day until delivery. At the age of 5 weeks, the body and brain weights of offspring were measured, brain organ coefficient was calculated, and the levels of norepinephrine (NE), dopamine (DA), and 5-hydroxytryptamine (5-HT) in cerebral cortex and hippocampus of offspring were detected.

Results The brain weight and brain organ coefficient of the 4.0 mg/kg nicotine treatment group were significantly lower than those of the other three groups (P < 0.05). In offspring cerebral cortex, the levels of NE, DA, and 5-HT of the three nicotine exposed groups were significantly lower than those of the control group (P < 0.05); the level of NE of the 4.0 mg/kg nicotine treatment group was significantly lower than those of the other two nicotine exposed groups (P < 0.05); the levels of DA of the 2.0 mg/kg and 4.0 mg/kg nicotine exposed groups were significantly lower than that of the 1.0 mg/kg nicotine exposed group (P < 0.05); the level of 5-HT of the 4.0 mg/kg nicotine exposed group was significantly lower than that of the 1.0 mg/kg nicotine exposed group (P < 0.05). In offspring hippocampus, the levels of NE and DA of the three nicotine exposed groups were significantly lower than those of the control group (P < 0.05); a dose-effect relationship was found between the DA level and the dose of nicotine treatment (P < 0.05); the level of 5-HT in the 4.0 mg/kg nicotine exposed group was significantly lower than those of the control group (P < 0.05).

Conclusion Gestational exposure to nicotine could influence the levels of monoamine neurotransmitters in the cerebral cortex and hippocampus of rat offspring, which might participate the neurodevelopmental toxicity induced by nicotine.