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 paraganglia and adrenal catecholamine stores in rabbit neonates. We compared pregnant rabbits injected with 0.01 mg x kg(-1) of dexamethasone (Dex) from day 24 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 of 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 were significantly higher in the Dex animals than in the untreated ones at every maturational stage studied. For saline animals, the levels were lower than in the Dex group and higher than in the untreated one. In adrenal glands, the same pattern was observed for noradrenaline only. These findings suggest that such a treatment has a positive long-term effect on catecholamine levels of both structures with a more marked effect on paraganglia, an extra-adrenal structure exerting a main function during the perinatal period in providing the child with catecholamine stores.