Stress and the hypothalamo-pituitary-adrenal axis: acute, chronic and immunological activation (original) (raw)

Successful existence depends on the ability to cope with an immense variety of complex challenges or stressors and to mount an 'appropriate' response to any particular situation. While the concept of stress is readily understood, a definition acceptable to more than a handful of individuals remains elusive. It is necessary therefore at the outset to clarify the context within which we have written the current review. We will utilize a simple definition based on the neuroendocrine response to stressors and for this purpose we shall limit our discussion to those events resulting in the activation of the hypothalamo-pituitary-adrenal (HPA) axis. The final stage of this activation is the secretion of glucocorticoids from the adrenal cortex.

Glucocorticoids have a wide range of actions affecting many aspects of bodily function including metabolism, inflammation and immunity. Glucocorticoids also control their own synthesis and release by completing a negative feedback loop at the level