3h cortisol

Plasma cortisol was measured with an extracted radioimmunoassay [17] (link) using hydrocortisone (H-4001; Sigma Chemical Company, St Louis, MO, USA) as standard. The assay used [3H]-cortisol (Amersham Pharmacia Biotech, UK, Buckinghamshire HP, England) as tracer and a dichloromethane extracion procedure with a mean (± standard error of the mean [SEM]) recovery of 93.2 ± 2.8%. There were 8 assays conducted, and the sensitivity ranged from 0.15 to 0.47 ng/mL with a mean of 0.33 ng/mL. The mean intra-assay coefficient of variation was 7.81%. The mean interassay coefficient of variation was 12.06%.
Oxytocin in plasma was measured using a Phoenix Pharmaceuticals Oxytocin Radioimmunoassay Kit (Belmont, CA, USA) following a similar procedure to that described by Marazziti [18] . There was a 100% cross-reactivity with oxytocin and no cross-reactivity with AVP. Nine assays were conducted and the sensitivity ranged from 0.3 to 2.3 pg/mL with a mean of 1.2 pg/mL. The mean intra-assay coefficient of variation was 5.22%, and the mean interassay coefficient of variation was 8.01%.

All samples were measured in a single assay. Serum cortisol concentrations were measured before and after 8 weeks of antidepressant treatment using an extracted RIA. RIA used hydrocortisone (H-4001, Sigma Chemical Company, St Louis, MO, USA) as a standard. The assay utilized ³H-cortisol (Amersham Pharmacia Biotech UK, Buckinghamshire HP, England) as tracer and a dichloromethane extraction procedure with a mean (± SEM) recovery of 91.2 ± 1.8%. All samples were measured in a single assay, which had a sensitivity of 0.54 ng/ml. The cross reactivity to chemicals that interfere with the assay result and their concentration (ug/dL) was checked. The cross reactivity of chemicals were: 11-Deoxycortisol (13.6%), cortisone (1.4%), dexamethasone (2.0%), corticosterone (8.0%), and prednisolone (32.2%).