Maternal nicotine exposure during gestation and lactation of rats induce microscopic emphysema in the offspring

The aim of this study was thus to determine whether maternal nicotine exposure during gestation and lactation will result in early emphysema in the lungs of the offspring. Female rats received nicotine subcutaneously during gestation and lactation. Nicotine administration commenced I day after mating and lasted until weaning on postnatal day 21. The offspring were exposed to nicotine via the placenta and mother's milk only. Lung tissue of the neonates was collected for analysis on postnatal days 14, 21, 35 and 42. The results show that maternal nicotine exposure had no effect on the total alveolar count (Na), mean alveolar volume (Valv), and airspace wall surface area per unit volume of lung tissue (AWUV) of the 14- and 21-day-old rat pups. However, the Na of the 35- and 42-day-old control animals was higher than that of the nicotine exposed animals. The Valv of the 35- and 42-day-old nicotine exposed rat pups was however larger than that of the control animals, whereas the AWUV of the 35- and 42-day-old control animals were bigger than that of the nicotine-exposed animals of the same age. The scanning electron micrographs showed a gradual flattening of the alveoli. It is therefore concluded that maternal nicotine exposure induced changes at gene level that renders the lungs of the offspring more susceptible to emphysema-like lesions.