Releasing hormone

Releasing hormones (also known as releasing factors or RFs) are a type of hormone that stimulate the release of another hormone from a downstream gland. They are produced in the hypothalamus and travel to the anterior pituitary gland via the hypophyseal portal system, where they stimulate the release of pituitary hormones.

Function

Releasing hormones are part of the endocrine system, a network of glands that produce and release hormones that help control many important body functions, especially the body's ability to change calories into energy that powers cells and organs. The hypothalamus uses releasing hormones to signal the anterior pituitary gland to produce and release hormones, which in turn regulate various body functions and other endocrine glands.

Types of Releasing Hormones

There are several types of releasing hormones produced by the hypothalamus. These include:

• Gonadotropin-releasing hormone (GnRH)
• Growth hormone-releasing hormone (GHRH)
• Thyrotropin-releasing hormone (TRH)
• Corticotropin-releasing hormone (CRH)
• Prolactin-releasing hormone (PRH)
• Somatostatin (also known as growth hormone-inhibiting hormone)

Each of these hormones stimulates the anterior pituitary gland to produce and release a specific hormone.

Clinical Significance

Releasing hormones can be used in medicine to diagnose endocrine disorders. For example, a GnRH stimulation test can be used to diagnose hypogonadism and precocious puberty. In addition, synthetic versions of releasing hormones can be used to treat certain medical conditions. For example, synthetic GnRH is used to treat prostate cancer and some fertility disorders.

See Also

• Hypothalamus
• Pituitary gland
• Endocrine system
• Hormone