Cigarette smoke causes changes in liver and spleen of mice newborn exposed during pregnancy.

Abstract

Cigarette smoking can lead to pivotal morphological changes in several human and animal tissues, especially when the exposure occurs during neonatal life. We evaluated the livers and spleens of C57BL/6 neonatal mice to determine possible morphological changes induced by exposure to cigarette smoke. In total, 15 C57BL/6 adult mice were used for mating, placing 2 female mice per male mouse for a 5-day period. Pregnant female mice were divided into 2 groups: the first group (ICS21) consisted of 5 female mice that were exposed to 4 cigarettes, 3 times daily for 21 days. They were subjected to 6 min of exposure per cigarette in an inhalation chamber. The second group (CG) consisted of 5 female mice that were not exposed to cigarette smoking and was used as a control group. Seven neonatal mice from both groups were weighed 24 h post-birth and then euthanized. Their livers and spleens were weighed and fixed for routine histological processing. Morphometric analysis was used to assess possible hepatic inflammation, measure hepatic glycogen and collagen deposition areas. Total spleen area, white pulp, and red pulp were identified. A reduction in body weight was observed in ICS21 mice as compared to CG mice, and a similar trend was observed in the liver and spleen weights. Histological analysis indicated the presence of more number of inflammatory cells in the ICS21 livers than that in the CG livers. Moreover, smaller hepatic glycogen deposition areas were observed in ICS21 mice than that in CG mice. However, no difference in hepatic collagen deposition was observed between the 2 groups. No differences were observed in the areas of the total organ and the white and red pulp areas between the 2 groups. However, the proportion of the white pulp and total area was lower in the ICS21 spleens than that in the CG spleens. Our results indicate that exposure to cigarette smoke during neonatal life can induce changes in fetal tissues, which translate to several changes in the organs of the neonatal mice.