Maternal Nicotine Effects on Lung Collagen Gene Expression in Newborn Rats

We evaluated the effects of maternal nicotine treatment on collagen gene expression in newborn rat lungs. Timed pregnant Sprague-Dawley rats were injected subcutaneously with nicotine tartrate (2 mg/kg/day) from day 3 to day 21 of gestation. A control group was injected with an equal volume of 0.9% NaCl. On days 1, 7, 14, and 21 after birth, rat pups were randomly selected from each group and lungs were removed for measurement of collagen gene expression and collagen contents by reverse transcription-polymerase chain reaction and histology, respectively. Body weights of nicotine-treated dams were lower than those of control dams from gestational days 5 to 21, and the values reached statistical significance on gestational days 17, 20, and 21. The body weight, lung weight, and lung/body weight ratio were comparable between control and nicotine-exposed rats. Lung collagen I and III mRNA expressions and collagen-staining pattern in alveolar septa were similar between control and nicotine-exposed rats during the study period. We conclude that maternal exposure to nicotine (2 mg/kg/Day) during pregnancy does not influence collagen gene expression or collagen contents in postnatal rat lungs.