PRENATAL STARVATION, BETAMETHASONE AND LUNG DEVELOPMENT IN NEWBORN RATS

This study examined the potential benefit of simultaneous transplacent al betamethasone, which accelerates fetal lung maturation. Pregnant ra ts were placed in one of 4 groups: Control (C), fed ad libitum until t erm and given daily physiological saline injections from day 15 of ges tation until term; Betamethasone (B), fed as group C but given daily p hysiological saline injections of 2.0 mg betamethasone/kg body weight from day 15 until term; Staved (S), given 50% rations from day 15 unti l term and injected as group C; Starved + Betamethasone (SE), fed as g roup S and injected as group B. Controls and group B did not differ in body or lung weight, protein or DNA, but group B lungs contained more lavageable and tissue surfactant. The S neonates weighed about 40% le ss than controls, with a proportional reduction in lung weight, DNA, p rotein or lavage and tissue phospholipids. Betamethasone may alleviate the impact of starvation on the developing lung by accelerating the p rocess of alveolarization which was solved by caloric deprivation.