Oxytocin and Stress Response

摘要

In response to a stressful unexpected experience, the brain activates a complex stress system that involves the organism in an adaptive response to the threatening situation. This stress system acts on several peripheral tissues and feeds back to the brain. One of its key players is oxytocin hormone. The neuropeptide, oxytocin (OT), has well-established roles during parturition and lactation. In addition to its peripheral actions, OT is released within multiple areas of the brain and influences behavioural and neuroendocrine responses to stress. Several studies suggest that oxytocin is implicated in the central control of responses to stress through modulation of corticotrophin releasing hormone (CRH). Intranasal OT application was associated with an inhibitory effect on adrenocorticotrophic hormone (ACTH) secretion and subsequent impairment of corticosterone secretion. This may be of importance for understanding and perhaps suggesting its utility to buffer stress. Synthesis and release of OT depend to a great extent on steroid hormones particularly on estradiol and corticosterone. Estrogens stimulate synthesis and release of OT and increase the number of OT receptors in some areas of the brain. However, the role of OT in mediating stress is variable and may also depend on gender and on external factors.