EN
Vasopressin (AVP) has fundamental role in the regulation of the hypothalamo-pituitary-adrenal axis, the main target of stress and adaptation. Its role is especially important during chronic load, which can induce anxiety and depression. The importance of AVP in stress and related mood disorders were studied in spontaneously mutated AVP-defi cient Brattleboro rats (di/di). AVP was confi rmed to be a prominent regulator of the adrenocorticotrop hormone secretion in wide range of stresses. Accompanied corticosterone elevation was reduced in di/di rats just occasionally and remained elevated longer. Endogenous AVP acts as a paracrine signal to facilitate the return of plasma corticosterone to basal levels. Behavioral studies confi rmed that di/di animals were less anxious in the defensive withdrawal test and revealed lower depressive indeces during forced swimming. Thus, AVP-antagonists are promising targets for drug development