A morphometric study of lung maturation in the adrenocorticotrophin-infused fetal lamb.

Adrenocorticotrophin (ACTH) effects on lung development were studied in sheep. ACTH was infused into 10 fetal lambs at 129 days of gestation at a rate of 29, 110 or 250 micrograms/day for 72 h, a time course which was independent of the mechanical and hormonal forces associated with labor. Lungs were compared with those of normal fetuses at term (day 147).

Lung development in the nephrectomized ovine fetus.

The effect of fetal nephrectomy on lung development was studied in sheep. Fetal kidneys were removed early in the canalicular stage of lung development (95 to 99 days of pregnancy) and lung structure examined during the alveolar stage (125 to 134 days of gestation). Progesterone and estradiol 17 beta concentrations in maternal and fetal plasma were normal for gestational age, thus indicating that the ewes were not close to labour at the time the fetuses were removed.