[Radioimmunologic determination of ACTH in the rabbit: stress-ACTH-corticosteroid relationship and diarrhea]

Plasma ACTH was measured in young and adult rabbits with a CEA-SORIN kit. The reliability of the analysis was controlled by liquid chromatography, several biochemical tests such as parallelism and reproducibility and several physiological tests such as plasma ACTH response to ethylic ether stress, to adrenalectomy, to dexamethasone and metopyrone. In young diarrhoeic rabbit plasma, ACTH (293 +/- 45 pg/ml) and corticosteroid (111 +/- 13 ng/ml) levels were significantly much higher than in young healthy rabbits (ACTH: 130 +/- 35 pg/ml; corticosteroids: 66 +/- 7 ng/ml). Furthermore, transporting young rabbits by car caused such violent stress that plasma ACTH levels increased from 52 +/- 11 to 130 +/- 35 pg/ml. A causal relationship between stress - ACTH and diarrhoea is discussed.