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 theconnective tissue frame-work of the neonatal lung, a process that is dependenton copper-dependent lysyl oxidase. It has been shown that, during the phase oflung development associated with alveolarization, maternal nicotine exposureresulted in a reduction in the copper content and thus conceivably in theactivity of lysyl oxidase of the neonatal lung. Therefore the aims of thisstudy were (a) to determine the effects of maternalnicotine exposure during gestation and lactation on neonatal lung development,and (b) to establish whether maternal coppersupplementation during gestation and lactation prevented the effect ofmaternal nicotine exposure on neonatal lung development. Pregnant rats wererandomly divided into four groups: the control group received saline; thesecond group received 1 mg nicotine (kgbodyweight)<emph type="7">-1 day<emph type="7">-1subcutaneously; the third group received 1 mg copper (kgbodyweight)<emph type="7">-1 day<emph type="7">-1;and the fourth group received both nicotine and copper in the same quantitiesas the previous two groups. Lung tissue of 14- and 42-day-old rat pups wereprocessed for light microscopy. Maternal nicotine exposure during gestationand lactation resulted in (a) decreased alveolar number,(b) reduced internal surface area and(c) increased alveolar volume. Copper supplementationduring gestation and lactation prevented the adverse effects of maternalnicotine exposure during gestation and lactation on the development of thealveolar region of the rat lung.