Most of the peptides first isolated from the hypothalamus have now also been shown to be formed within pituitary cells where they form intrinsic paracrine (cell-to-cell) and autocrine (cell-to-itself) regulatory systems. They are also found outside the hypothalamus where they may act as mediators of affective state and biological rhythms; or as regulators of visceral function, activity, body temperature, and eating and drinking behaviour.
Some of the hypothalamic factors exert physiologically significant inhibitory actions on anterior pituitary function. These inhibitory factors interact with the respective releasing factor to exert dual control of secretion of prolactin, growth hormone (GH), and thyroid-stimulating hormone/thyrotrophin (TSH).
