Maternal tobacco smoke exposure programs increased lung static compliance in female rat offspring (715.5)

Abstract

Background: Intrauterine growth restriction (IUGR) increases the risk for postnatal lung disease, in part, through programmed alterations in gene expression patterns. A consequence of altered gene expression programs in the developing lung is changes in lung compliance and resistance. In a rat model of surgically‐induced IUGR (sIUGR), male rat pups have increased compliance and decreased resistance, while female rat pups are unaffected. Maternal tobacco smoke (MTS) exposure also results in IUGR. However, the effects of MTS‐induced IUGR on lung compliance and resistance are unknown.Objective: We hypothesized that MTS exposure alters lung compliance and resistance in rat offspring.Design/Methods: Maternal rats received tobacco smoke exposure from gestational day 11 to term. Pups were delivered at term and cross‐fostered to a control dam until they were weaned at postnatal day 21 (d21). At d21, rats were anesthetized and paralyzed, and closed chest, lung static compliance and lung resistance mechanics were measured using the FlexiVent System.Results: MTS significantly increased lung compliance in female (118 ± 4%, p=0.02), but not male rat offspring. Lung resistance was not affected by MTS in either male or female rat offspring.Conclusion: MTS‐induced IUGR leads to a long‐term increase in lung compliance in female rats. We previously showed that increased compliance in male sIUGR rat pups is accompanied by decreased elastin mRNA variant expression. We therefore speculate that MTS‐induced increased compliance in female rat pups will be accompanied by decreased elastin mRNA variant expression.Grant Funding Source: Supported by the APS STRIDE Fellowship Award