TRH effect on hormones?

TRH effect on hormones?

• A. TRH increases TSH and Prolactin
• B. TRH increases GH and TSH
• C. TRH decreases TSH
• D. TRH has no effect on prolactin

Answer: (A)

Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the anterior pituitary to release two hormones: TSH from thyrotrophs and prolactin from lactotrophs. When TRH binds its receptors on thyrotrophs, it triggers TSH synthesis and secretion, boosting thyroid hormone production. It also binds to lactotrophs, promoting prolactin release. Growth hormone is mainly controlled by GHRH and somatostatin, not TRH, so TRH’s effect on GH is minimal and not a primary action. TRH does not decrease TSH, and it clearly increases prolactin, so the correct statement is that TRH increases both TSH and prolactin. Clinically, this underlies the TRH stimulation test, where both hormones rise in response.

Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates the anterior pituitary to release two hormones: TSH from thyrotrophs and prolactin from lactotrophs. When TRH binds its receptors on thyrotrophs, it triggers TSH synthesis and secretion, boosting thyroid hormone production. It also binds to lactotrophs, promoting prolactin release. Growth hormone is mainly controlled by GHRH and somatostatin, not TRH, so TRH’s effect on GH is minimal and not a primary action. TRH does not decrease TSH, and it clearly increases prolactin, so the correct statement is that TRH increases both TSH and prolactin. Clinically, this underlies the TRH stimulation test, where both hormones rise in response.