Prolactin Stimulation by Thyrotropin-Releasing Hormone in a Patient with Isolated Thyrotropin Deficiency

Abstract
PROLACTIN and thyrotropin (TSH) are protein hormones that appear to be produced by different cell populations of the anterior pituitary gland.1 TSH secretion is stimulated by thyrotropin-releasing hormone (TRH), a releasing factor from the hypothalamus whose effects have been well studied in man.2 Prolactin secretion, on the other hand, appears to be under tonic inhibition by a hypothalamic inhibitory factor,1 but studies in animals have suggested an additional hypothalamic stimulating factor as well.3 4 5 Recently, it has been shown in tissue culture6 and intact man7 , 8 that TRH promotes pituitary prolactin secretion in a manner qualitatively and quantitatively similar to its stimulation . . .