Effects of antenatal hydrocortisone on tidal volumes in spontaneously breathing preterm newborn rabbits. Possible mediation by adrenal catecholamines.
Rabbit fetuses were injected on day 26 of gestation with hydrocortisone (2 mg) and delivered by hysterotomy 2 days later. The animals were tracheotomized at birth, and tidal volumes and esophageal pressures were recorded during spontaneous ventilation at standardized intervals from the first breath to the age of 2 h. In a subgroup of animals, the catecholamine content was measured in the adrenal glands. In comparison with littermate controls, tidal volumes were enlarged in hydrocortisone-treated neonates at the first breath and 60 min after birth; however, this effect was associated with an increased incidence of intra-alveolar hemorrhage. Hydrocortisone-treated animals also had a significantly increased adrenal content of adrenaline. Our data confirm a modest beneficial effect of antenatal hydrocortisone treatment on the fetal lung and suggest that this might in part be mediated by adrenal catecholamines. Stimulation of beta-adrenergic receptors could thus potentiate the effect induced by direct influence of glucocorticoids on fetal lung maturation.
Hedner
T
T
Department of Pharmacology, University of Göteborg, Sweden.
Bergman
B
B
Freyschuss
U
U
Grossmann
G
G
Robertson
B
B
D000311:Adrenal Glands / Q000196:embryology* / Q000378:metabolism; D000818:Animals; D002395:Catecholamines / Q000502:physiology*; D005325:Fetal Organ Maturity; D005865:Gestational Age; D006854:Hydrocortisone / Q000494:pharmacology*; D008168:Lung / Q000187:drug effects / Q000196:embryology*; D011650:Pulmonary Alveoli / Q000196:embryology; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000502:physiology; D012119:Respiration; D013990:Tidal Volume
D002395:Catecholamines; D011943:Receptors, Adrenergic, beta; D006854:Hydrocortisone