Hypothalamic–pituitary–adrenal axis mediators (HPA axis mediators) (HPA axis mediators)

The hypothalamic–pituitary–adrenal (HPA) axis mediators constitute a complex neuroendocrine system responsible for orchestrating the body's response to stress and maintaining homeostatic balance (StatPearls, 2023). This system operates through a hormonal cascade: the hypothalamus secretes corticotropin-releasing hormone (CRH), which triggers the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, which in turn stimulates the adrenal cortex to produce glucocorticoids, primarily cortisol (NCBI, 2011). These mediators exert their effects by binding to specific receptors, including the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), influencing a wide array of physiological processes such as glucose metabolism, immune function, and inflammatory responses (PubMed, 2017). Dysregulation of the HPA axis, characterized by either hypercortisolism or hypocortisolism, is central to the pathogenesis of disorders like Cushing's syndrome, Addison's disease, and various psychiatric conditions including major depression and PTSD (NIH, 2022). Therapeutic strategies targeting these mediators include the use of synthetic glucocorticoids for hormone replacement, GR antagonists to block excessive cortisol action, and steroidogenesis inhibitors to reduce hormone production (PubChem, 2024). Consequently, the HPA axis mediators are pivotal targets in both endocrinology and psychiatry for managing stress-related and metabolic pathologies.

Other names

HPA axisStress axisHypothalamic-pituitary-adrenal systemHPA system

Glucocorticoid receptor agonism, Glucocorticoid receptor antagonism, 11-beta-hydroxylase inhibition, Somatostatin receptor agonism, Steroidogenesis inhibition