New Study Finds That Cigarette Smoke Exposure Impairs Infant Lungs

Main Category: Smoking / Quit Smoking
Also Included In: Respiratory / Asthma;  Pediatrics / Children's Health
Article Date: 07 Apr 2008 - 4:00 PST

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US researchers report that exposure to cigarette smoke inhibits innate gene expression and impairs alveolar growth in neonatal mice.

Sharon McGrath-Morrow from John Hopkin Medical Institute wrote in the American Journal of Respiratory Cell and Molecular Biology that their findings may in part explain the increased incidence of respiratory symptoms in infants and children exposed to cigarette smoke.

Infants exposed to cigarette smoke are at higher risk for sudden infant death syndrome, lower respiratory tract infections, and small airway disease, compared with infants not exposed to cigarette smoke, suggesting that perinatal life represents a period of vulnerability during which exposure to cigarette smoke may impair lung immunity and lung growth.

To investigate the effects of cigarette smoke exposure on the neonatal lung, the researchers exposed neonatal mice to cigarette smoke for the first 2 weeks of life.

Pulmonary gene-expression profiling revealed that cigarette exposure significantly inhibited type 1 and type 2 interferon pathway genes in neonatal lungs, compared with age-matched control lungs.

In addition, lung volumes at 8 weeks of age were modestly but significantly decreased in mice exposed to cigarette smoke in the neonatal period compared with age-matched controls.

The authors said, "We found that perinatal lungs are susceptible to the effects of cigarette smoke exposure. In neonatal mice, daily exposure to cigarette smoke for the first 2 weeks of life inhibited the expression of many genes in the lung that are relevant to the innate immune response."

The team concludes: "Our murine model of cigarette smoke-induced neonatal lung injury may be useful in investigating pathways that are disrupted or altered in developing lungs exposed to cigarette smoke, and may help with understanding the overall detrimental effects of smoke exposure on developing lungs."

http://www.ash.org.uk