[A test for evaluation of pituitary-adrenal axis disregulation]

In rat models, a modification of the fast feedback paradigm for the pituitary adrenocortical system applied to detect posttraumatic stress disorder (PTSD) was developed. Both standard and modified methods were used. In contrast to the standard method (injection of exogenous cortisol), the new modification suggested measuring blood corticosterone, rather than adrenocorticotropic hormone, at the early stages of development of the stress reaction (3, 10, 30, and 60 min of the exposure to stress factors). With the suggested modification, the fast feedback phenomenon was studied in reliable rat models of PTSD (stress-restress) and depression (learned helplessness). Fast pathological inhibition of the pituitary adrenocortical system by the fast feedback mechanism was revealed only during the simulated PTSD but not in the depressive-like state, which supported the specificity and validity of the developed modification of the test. Thus, the proposed methodological modification is a valid tool for diagnostics of the PTSD-specific fast feedback inhibition of the pituitary adrenocortical system in the animal models of this psychopathology.