Following isolation, ARCs were plated to laminin-coated plates and cultured overnight in serum-free DMEM, as described previously.12 ARCs were next challenged with fetal calf serum (FCS; 10%), dexamethasone (Dex; 10, 100, or 1000 nM), insulin (1, 10, or 100 nM), leptin (1, 10, or 100 mM), angiotensin II (AngII; 0.1, 1, or 10 μM), or 9-cis retinoic acid (9-cisRA; 0.1, 1, or 10 μM). ARCs were terminated after either 3 or 6 hours of challenge, after which bmal1 expression was measured by real-time RT-PCR, as described previously.12 Control ARCs were cultured in DMEM supplemented with the test agent’s vehicle only. ARCs cultured in the presence of FCS served as positive controls. FCS and dexamethasone significantly (p<0.05) increased bmal1 expression at all concentrations investigated.