Fung Y K, Lau Y S
University of Nebraska Medical Center, College of Dentistry, Department of Oral Biology, Lincoln 68583-0740.
Pharmacol Biochem Behav. 1989 May;33(1):1-6. doi: 10.1016/0091-3057(89)90419-x.
Previously we observed that chronic nicotine-treated adult rats developed locomotor hyperactivity which was mediated by changes in nicotinic and dopaminergic receptors in the striatum. In this study, we further examined if such changes would also occur in pups that were prenatally exposed to nicotine. Fourteen-day-old offspring from dams which were implanted with osmotic minipumps containing nicotine (1.5 mg/kg/day) throughout the entire gestational period were employed in this investigation. Prenatal nicotine treatment lowered the number of male pups born and reduced the postnatal gain in body weight and length of both male and female offspring. Prenatal exposure to nicotine did not alter the motor coordination of the pups. A decrease in the number of striatal dopaminergic receptor binding sites (Bmax) was detected in the male pups, however an increase in the ligand affinity to the receptors (1/KD) had been simultaneously detected. No change in the characteristics of nicotinic receptor binding sites and the levels of dopamine and its metabolite, 3,4-dihydroxyphenylacetic acid was found in the striatal region. The present study indicates that prenatal exposure to nicotine may cause changes in growth and development of the animals. However, in comparison to chronic nicotine-treated adult rats, prenatal exposure to nicotine had only modified the dopaminergic receptor system in the striatal region of male offspring.
此前我们观察到，经慢性尼古丁处理的成年大鼠会出现运动性多动，这是由纹状体中烟碱样和多巴胺能受体的变化介导的。在本研究中，我们进一步研究了这种变化是否也会发生在产前暴露于尼古丁的幼崽身上。本研究采用了在整个妊娠期植入含有尼古丁（1.5毫克/千克/天）的渗透微型泵的母鼠所产的14日龄后代。产前尼古丁处理降低了出生雄性幼崽的数量，并减少了雄性和雌性后代出生后的体重增加和体长增长。产前暴露于尼古丁并未改变幼崽的运动协调性。在雄性幼崽中检测到纹状体多巴胺能受体结合位点数量（Bmax）减少，但同时检测到配体与受体的亲和力增加（1/KD）。在纹状体区域未发现烟碱样受体结合位点特征以及多巴胺及其代谢物3,4-二羟基苯乙酸水平的变化。本研究表明，产前暴露于尼古丁可能会导致动物生长发育的变化。然而，与经慢性尼古丁处理的成年大鼠相比，产前暴露于尼古丁仅改变了雄性后代纹状体区域的多巴胺能受体系统。
