Abnormal prenatal lung development resulting from maternal zinc deficiency in rats

The effect of maternal zinc deficiency during gestation on fetal lung development was studied. Sprague-Dawley rats were fed from the day of mating (day zero) a zinc deficient diet (0.4 +/- 0.1 ppm zinc) ad libitum, or a zinc supplemented control diet (100 ppm zinc) either ad libitum or with restricted intake. Fetuses were removed by cesarean section on days 17 to 21 of gestation. Fetuses of zinc deficient dams had smaller lungs both in absolute weight and relative to body weight on all days than did either ad libitum-fed or restricted-intake controls. On days 20 and 21 of gestation, concentration of fetal lung lecithin and phosphatidylethanolamine was lower in zinc deficient fetuses than in control groups, indicating a reduced production of pulmonary surfactant. The lecithin to sphingomyelin ratio of amniotic fluid was lower in zinc deficient rats than in controls on days 19, 20, and 21 of gestation. On days 18 through 21 of gestation, fetal lung DNA concentration in zinc deficient fetuses was lower than in controls, but there were no differences in fetal lung zinc concentration. Histological examination of lungs from zinc deficient fetuses at term showed air spaces that were slightly collapsed with smaller lumina of the alveolar ducts than in controls.