Brain glucocorticoid receptors and their role in behavioural teratogenicity of synthetic glucocorticoids.

Abstract

The distribution of glucocorticoid receptors (GR) in rat brain during development (postnatal days 3-16) was investigated and the prevalence of GR number was found in the cerebellum, the fastest growing part of perinatal brain. Dexamethasone (D) administration (0.04-3 mg . kg-1 s.c.) in 7-day-old rats induced dose-dependent depletion of brain cytosol GR with a 70% depletion after the smallest dose. Long-term effects of this GR mediated insult (D 1.0 and 0.2 mg . kg-1 s.c.) manifested themselves in adult rats as structural and biochemical brain deviations (especially in the cerebellum and hippocampus), behavioural abnormalities and reproduction disturbances. These sequels were detectable after D doses equal to clinical dosage in obstetrics and neonatology (0.2-0.6 mg . kg-1).