Influence of maternal nicotine exposure on neonatal rat lung structure: protective effect of ascorbic acid.

The aims of this study were (1) to determine and quantify the adverse effects of maternal nicotine exposure during pregnancy and lactation on neonatal rat lung development, and (2) to establish whether ascorbic acid will protect the neonatal rat lung against the adverse effects of maternal nicotine exposure. Pregnant rats received nicotine (1 mg/kg body mass/day) subcutaneously during gestation and lactation. A second group received nicotine and ascorbic acid (1 mg/kg body mass/day). The control animals received saline subcutaneously. The results illustrate that maternal nicotine exposure results in (a) a decreased (P < 0.001) radial alveolar count (RAC), (b) an increase (P < 0.001) in destructive index (DI), (c) an increased (P < 0.001) linear intercept (Lm), (d) an increased (P < 0.001) abnormal alveolar attachment index (AAA) (e) and an increase in septal cellularity. Ascorbic acid does not protect fetal lung development against the adverse effects of maternal nicotine exposure. However, after birth ascorbic acid prevents further deterioration of the DI, AAA and Lm, whereas the RAC and thus the number of alveoli was even higher than in control neonatal rat lung. No further increase in cellularity occurred. The reason for this response to ascorbic acid supplementation is under investigation.