The hypothalamic–pituitary–adrenal (HPA) axis is the regulation of neuroendocrine system consists of three components: the paraventricular nucleus (PVN) of hypothalamus, the anterior lobe of the pituitary gland and the cortex of adrenal glands (Jacobson and Sapolsky, 1991; Kino and Chrousos, 2004b; Nader et al., 2010). A mainly part of the common mechanism for interactions between HPA axis systems is the neuroendocrine regulation that response to stress. In stress response period, corticotropin-releasing hormones (CRH) or arginine vasopressin (AVP) are produced by the hypothalamus when the body has high stress, and release them into the anterior lobe of the pituitary gland to stimulate adrenocorticotropic hormones (ACTH) secretion (Chrousos,
