ACTH

ACTH, or adrenocorticotrophic hormone, is a hormone produced by the pituitary gland, a pea-sized gland located at the base of the brain. It plays a key role in the body’s response to stress by acting as a chemical messenger between the brain and the adrenal glands.

Here’s how it works:

1. Stress triggers: When your dog experiences physical or emotional stress, the hypothalamus, another part of the brain, releases a hormone that signals the pituitary gland to release ACTH.
2. Stimulating the adrenals: ACTH travels through the bloodstream and reaches the adrenal glands located near the kidneys. It stimulates the adrenal glands to produce cortisol, often called the “stress hormone.”

If ACTH is over-produced by a pituitary tumour, it causes excess cortisol production and therefore Cushing’s disease (pituitary-dependent Cushing’s).

Synthetic ACTH is used as part of testing for Cushing’s disease in an ACTH-stimulation test.