Dexamethasone acutely down-regulates genes involved in steroidogenesis in stallion testes

摘要

In rodents, livestock and primate species, a single dose of the synthetic glucocorticoid dexamethasone acutely lowers testosterone biosynthesis. To determine the mechanism of decreased testosterone biosynthesis, stallions were treated with O.lmg/kg dexamethasone 12 h prior to castration. Dexamethasone decreased serum concentrations of testosterone by 60% compared to saline-treated control stallions. Transcriptome analyses (microarrays, northern blots and quantitative PCR) of testes discovered that dexamethasone treatment decreased concentrations of glucocorticoid receptor alpha {NR3C1), alpha actinin 4 (ACTN4), luteinizing hormone receptor (LHCGR), squalene epoxidase {SQLE), 24-dehydrocholesterol reductase {DHCR24), glutathione S-transferase A3 {GSTA3) and aromatase (CYP19A1) mRNAs.