title: Effects of antenatal hydrocortisone on tidal volumes in spontaneously breathing preterm newborn rabbits. Possible mediation by adrenal catecholamines.
abstract: 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.
authors.affiliation: Department of Pharmacology, University of Göteborg, Sweden.
authors.forename: T
authors.initials: T
authors.lastname: Hedner
authors.forename: B
authors.initials: B
authors.lastname: Bergman
authors.forename: U
authors.initials: U
authors.lastname: Freyschuss
authors.forename: G
authors.initials: G
authors.lastname: Grossmann
authors.forename: B
authors.initials: B
authors.lastname: Robertson
mesh_terms: 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
chemical_list: D002395:Catecholamines; D011943:Receptors, Adrenergic, beta; D006854:Hydrocortisone