Ultrastructure of rat fetal lung after various glucocorticoid treatments

Pregnant rats were inected on gestation days 12 and 13 with different doses of betamethasone (0.18, 0.42, 06mg/injection), dexamethasone (0,24, 0.40, 0.56mg)), of saline (controls), and fetal lungs obtained at 21 gestation days. Luminal lining cell size, glycogen content, cytoplasmic organelles, and interstitial cells were effected by all doses of glucocorticoids except the 25 mg cortisone. Mitochondria were vacuolated only in the 50 mg cortisone rats. Alveolar septa were reduced in thickness in all other treated rats, capillaries were more numerous and nearer the lumen, with the greastest number of changes ocurring inthe dexamethasone treated rats. The most severe alterations also ocurred in these rats including disruption of or deposition of lipid in interstitial cells, greatly enhanced intercellular space devoid of cells or tissue, disruption or blebbing of capillary endothelium, lucency hydration and disruption and disruption of type I cells, and all of these repsonses were dose related