What is the Origin of Corticotropin Suppression?

This concept is foundational to the understanding of the Hypothalamic-Pituitary-Adrenal (HPA) axis, the central stress response system. The term originates from the Greek words kortex (bark) and tropos (turning), referring to its action on the adrenal cortex. Clinically, it is a key diagnostic indicator when assessing pituitary-adrenal function, particularly in cases of long-term steroid use.

What is the Mechanism of Corticotropin Suppression?

High levels of cortisol or synthetic glucocorticoids bind to glucocorticoid receptors in the hypothalamus and pituitary gland. This binding inhibits the release of Corticotropin-Releasing Hormone (CRH) from the hypothalamus and, subsequently, the release of ACTH from the pituitary. The resulting low ACTH signal reduces the stimulation of the adrenal fasciculata zone, leading to a marked decrease in endogenous cortisol production.

Corticotropin Suppression ∞ Area

Corticotropin Suppression

Meaning

Corticotropin suppression denotes the clinical phenomenon where the secretion of Adrenocorticotropic Hormone (ACTH), also known as corticotropin, from the anterior pituitary gland is reduced below its physiological baseline. This reduction typically occurs as a negative feedback response to elevated levels of circulating glucocorticoids, whether endogenous or exogenous. Suppression of ACTH directly leads to decreased cortisol synthesis by the adrenal cortex, a critical state in endocrinology.