The effect of grand maternal nicotine exposure during gestation and lactation on lung integrity of the F2 generation

Abstract

Maternal nicotine exposure during gestation and lactation adversely affects lung development in the offspring. It has been suggested that the "program" that control long-term maintenance of the structural integrity of the lung may be compromised. The aim of the study was to establish whether the effect of grand-maternal nicotine exposure during gestation and lactation can be transferred to the F2 generation. After mating, rats were randomly divided into two groups (F0). One group received nicotine (1 mg/kg body weight/day). The controls receive saline. Body weight (BW), lung volume (Lv), linear intercept (Lm), alveolar wall thickness (Tsept), senescent and proliferating cell numbers were used to evaluate changes in the lung structure of the offspring (F1). The F1 generation was divided into four groups, namely, (1) control (F1 males mated with F1 females, (2) NmCf (F1 nicotine exposed male mated with F1 control female), (3) NfCm (F1 nicotine exposed female mated with F1 control male), and (4) NmNf (F1 male exposed to nicotine mated with F1 female also exposed to nicotine). The F1 nicotine exposed males and females were exposed to nicotine via the placenta and mother's milk (F0 generation) only. The F2 progeny was never exposed to nicotine. Grand-maternal nicotine (F0) resulted in parenchymal deterioration and emphysema in the F2 progeny due to increased numbers of premature senescent cells together with a slower cell proliferation. The transfer of premature aging characteristics from the F1 progeny to the F2 progeny is via the male and female germ cell line. Grand-maternal nicotine exposure induces structural changes in the lungs of the F2 generation that resembled premature aging.