Protirelin

Protirelin (also known as thyrotropin-releasing hormone or TRH) is a tri-peptide hormone produced in the hypothalamus. It plays a crucial role in the regulation of the thyroid gland and the production of thyroid hormones.

Function

Protirelin stimulates the anterior pituitary gland to release thyroid-stimulating hormone (TSH). TSH, in turn, stimulates the thyroid gland to produce and release thyroxine (T4) and triiodothyronine (T3), the primary hormones responsible for regulating the body's metabolism.

Structure

Protirelin is a small peptide hormone composed of three amino acids: glutamic acid, histidine, and proline. It is synthesized as a larger precursor molecule, prepro-TRH, which is then cleaved to produce the active hormone.

Clinical significance

Protirelin is used in the TRH stimulation test, a diagnostic procedure used to assess thyroid function. In this test, protirelin is administered to stimulate the release of TSH, and the levels of TSH in the blood are then measured. This test can help diagnose conditions such as hypothyroidism and hyperthyroidism.

Protirelin has also been investigated for its potential therapeutic uses. For example, it has been studied for its potential to treat depression, as it appears to have antidepressant effects in some individuals.

See also

• Thyroid function tests
• Thyroid disease
• Endocrinology