van de Kamp J L, Collins A C
Institute for Behavioral Genetics, University of Colorado, Boulder 80309.
Pharmacol Biochem Behav. 1994 Apr;47(4):889-900. doi: 10.1016/0091-3057(94)90293-3.
Maternal smoking during pregnancy may affect development of the child, but little is known about potential mechanisms of these effects. Since chronic nicotine treatment alters brain nicotinic receptors in adults and also evokes tolerance which is regulated by genetic factors, pregnant mice of two inbred strains underwent chronic nicotine infusion to determine whether the developmental pattern of mouse brain nicotinic receptors would be altered. C3H/2ibg and C57BL/6ibg mice were infused SC with saline or 2.0 mg/kg/h nicotine during the last half of pregnancy. The developmental profiles of [3H]nicotine and alpha-[125I]bungarotoxin binding in seven brain regions obtained from the offspring were measured. Prenatal nicotine treatment increased levels of [3H]nicotine binding at birth in the C3H hypothalamus, hippocampus, and possibly the cortex, and in the C57BL cortex. At later ages (20-30 days), [3H]nicotine binding was elevated in the C3H hindbrain, hippocampus, striatum, midbrain, and possibly the cortex. The C57BL hindbrain, hippocampus, midbrain, and cortex also showed increased binding at 20-30 days. Little, if any, effect of prenatal nicotine treatment was observed on the development of the alpha-[125I]bungarotoxin binding site. Since upregulated [3H]nicotine binding returns to control levels in adult animals within seven days following termination of chronic nicotine infusion, it is unlikely that simple upregulation is responsible for the changes observed in 20-30-day-old mouse brains.
孕期母亲吸烟可能会影响孩子的发育，但这些影响的潜在机制却鲜为人知。由于慢性尼古丁处理会改变成年动物大脑中的烟碱型受体，还会引发由遗传因素调节的耐受性，因此对两个近交系的怀孕小鼠进行了慢性尼古丁输注，以确定小鼠大脑烟碱型受体的发育模式是否会发生改变。在怀孕的最后半个阶段，给C3H/2ibg和C57BL/6ibg小鼠皮下注射生理盐水或2.0毫克/千克/小时的尼古丁。测量了从后代获得的七个脑区中[3H]尼古丁和α-[125I]银环蛇毒素结合的发育情况。产前尼古丁处理使出生时C3H小鼠下丘脑、海马体以及可能的皮质，还有C57BL小鼠皮质中的[3H]尼古丁结合水平升高。在稍后的年龄阶段（20 - 30天），C3H小鼠的后脑、海马体、纹状体、中脑以及可能的皮质中[3H]尼古丁结合升高。C57BL小鼠的后脑、海马体、中脑和皮质在20 - 30天时也显示出结合增加。产前尼古丁处理对α-[125I]银环蛇毒素结合位点的发育几乎没有观察到影响。由于在慢性尼古丁输注终止后的七天内，上调的[3H]尼古丁结合在成年动物中会恢复到对照水平，所以简单的上调不太可能是20 - 30日龄小鼠大脑中观察到的变化的原因。
