Induction of a hyperanxious state by antenatal dexamethasone:: A case for less detrimental natural corticosteroids

Background: Synthetic glucocorticoids are commonly prescribed during pregnancy, despite a lack of systematic investigations of their potential impact on the developing brain and neurological and behavioral performance. Methods. Neuroendocrine parameters and behavior in the adult offspring of pregnant Wistar rats treated antenatally with either dexamethasone (DEX) or corticosterone (CORT) were monitored; DEX (.1 mg/kg and 1 mg/kg) and CORT (25 mg/kg) were given to pregnant rat dams on gestation days 18 and 19. Results: Despite normal basal levels of corticosterone, the adult offspring of mothers given DEX or CORT displayed abnormal responses in the dextamethazone-suppresion test. Neither treatment influenced spatial memory performance, but both DEX and CORT facilitated development of depression-like behavior following chronic stress. The latter finding demonstrates that high-dose antenatal corticotherapy can impair the organism's resilience to stress in adulthood. Interestingly, comparison of the progeny of CORT-treated and DEX-treated mothers revealed that the latter were more anxious. Conclusions: Since DEX and CORT differ in their affinity for glucocorticoid and mineralocorticoid receptors and corticosteroid-binding globulin, our findings emphasize The need to consider the pharmacologic properties of antenatal corticotherapies and demonstrate the potential long-term benefits of ligands that can bind to both receptors.