We quantified CORT and T using a standard competitive binding radioimmunoassay as described in Mendonça et al. (1996) and Hopkins et al. (1997). We used ether extraction to separate steroid hormones from 10 to 20 μL of plasma, and tested the samples in duplicate. We purchased antibodies from Esoterix (Calabasas Hills, CA, USA) and used a standard charcoal–dextran separation technique. After correction for plasma volume and percentage of extraction efficiency, we expressed the plasma hormone content in nanograms per milliliter of plasma (ng/mL). The percentage of efficiency extraction for CORT and T was on average 79.0 and 76.0%, respectively. Inter‐ and intra-assay variation averaged 4.20 and 32.30% for CORT, and intra-assay variation averaged 7.80% for T. All samples for T measurements were run in a single assay.