Hypothalamic regulation of thyroid-stimulating hormone and prolactin release : the role of thyrotrophin-releasing hormone

Thyrotrophin-releasing-hormone (TRH), a tripeptide, is produced by hypothalamic neurons and transported along their axons to the median eminence (ME). From there it is released at nerve terminals into hypophyseal portal blood. It is then transported to the anterior pituitary gland where it stimulates the function of the 11 thyrotrophs and lactotrophs, which synthesize and release thyroid-stimulatinghormone (TSH) and prolactin (PRL) respectively. TSH, in turn, stimulates the secretion of triiodothyronine (T3) and thyroxine (T4) from the thyroid gland. PRL is involved in a broad spectrum of biological activities. In this thesis its role in the initiation and maintanance of lactation will be described.