In many cell types, hypoxia upregulates the expression of the pro-apoptotic gene Bnip3 which results in cell death. Bnip3 mRNA is also increased by RU28362, a glucocorticoid receptor specific agonist, and this correlates with augmented cell death in primary cortical neurons (Sandau and Handa, SFN. Abst. 837.21, 2004). In this study, we further examined Bnip3 mRNA regulation in primary cortical neurons by hypoxic insult in conjunction with glucocorticoid treatment. Additionally, we determined if increases in Bnip3 mRNA correlated with increases in cell death. Cortical neurons were harvested from embryonic day 18 rat fetuses. Neurons were treated with 1 of 3 doses of RU28362 (0.1, 1.0, or 10.0nM) or vehicle and maintained in normoxic (20% O2) or hypoxic (1% O2) conditions for 72 hours. Bnip3 mRNA expression was assayed by quantitative real time RT-PCR. Hypoxia caused a 0.5 fold increase in Bnip3 mRNA levels compared to vehicle treated normoxic cells. However, cells treated with RU28362 in conjunction with hy...