Available ELISA kit (MD Biosciences, Inc.) using the procedure recommended by the manufacturer. The detection limit of the kit is 0.46 pg/ml. The antibody in the kit specifically reacts with ACTH and has less than 1 cross-reactivity with alpha-MSH (Melanocyte-stimulating hormone) and betaendorphin. ACTH concentrations (pg/ml) were determined by comparing samples to a standard curve generated with