Maternal copper supplementation protects the neonatal rat lung against the adverse effects of maternal nicotine exposure

Abstract

Maternal nicotine exposure interferes with the extracellular formation of the connective tissue frame-work of the neonatal lung, a process that is dependent on copper-dependent lysyl oxidase. It has been shown that, during the phase of lung development associated with alveolarization, maternal nicotine exposure resulted in a reduction in the copper content and thus conceivably in the activity of lysyl oxidase of the neonatal lung. Therefore the aims of this study were (a) to determine the effects of maternal nicotine exposure during gestation and lactation on neonatal lung development, and (b) to establish whether maternal copper supplementation during gestation and lactation prevented the effect of maternal nicotine exposure on neonatal lung development. Pregnant rats were randomly divided into four groups: the control group received saline; the second group received 1 mg nicotine (kg bodyweight)^–1 day^–1 subcutaneously; the third group received 1 mg copper (kg bodyweight)^–1 day^–1; and the fourth group received both nicotine and copper in the same quantities as the previous two groups. Lung tissue of 14- and 42-day-old rat pups were processed for light microscopy. Maternal nicotine exposure during gestation and lactation resulted in (a) decreased alveolar number, (b) reduced internal surface area and (c) increased alveolar volume. Copper supplementation during gestation and lactation prevented the adverse effects of maternal nicotine exposure during gestation and lactation on the development of the alveolar region of the rat lung.