Neonatal catecholamine content of adrenal and extra-adrenal chromaffin tissue after prenatal exposure to dexamethasone

We investigated the effects of prenatal exposure to dexamethasone on paraga nglia and adrenal catecholamine stores in rabbit neonates. We compared preg nant rabbits injected with 0.01 mg.kg(-1) of dexamethasone (Dex) from day 2 4 to day 27 of gestation to an untreated group of unmanipulated rabbits. A group injected with 0.9% saline solution was added to evaluate the effect o f injection and handling. Catecholamines were assessed by HPLC in offspring paraganglia and adrenal glands on days 0, 1, and 7 after birth. Data were analyzed by a two-factor ANOVA and Bonferroni-Dunn and t tests. Statistical significance was accepted at p < 0.05. Paraganglia catecholamine levels we re significantly higher in the Dex animals than in the untreated ones at ev ery maturational stage studied. For saline animals, the levels were lower t han in the Dex group and higher than in the untreated one. In adrenal gland s, the same pattern was observed for noradrenaline only. These findings sug gest that such a treatment has a positive long-term effect on catecholamine levels of both structures with a more marked effect on paraganglia, an ext ra-adrenal structure exerting a main function during the perinatal period i n providing the child with catecholamine stores.