After the combined pituitary stimulation test (100 micrograms human CRH, 100 micrograms GnRH, 100 micrograms << GH-releasing hormone >>, and 200 micrograms TRH), the ACTH peak (maximum increase at 30 min) was significantly blunted by [[ loperamide ]] from 9 +/- 1 to 4 +/- 1 pmol/L (P less than 0.001) and the area under the curve of ACTH from 0-120 min was reduced from 35 +/- 5 to 23 +/- 4 pmol/L.2 h (P less than 0.05).