Neuroendocrine cell peptides are GRP, the mammalian form of bombesin, and CGRP; these substances exert direct mitogenic effects on epithelial cells and exhibit many properties akin to growth factors. Specialized groups of neuroendocrine cells can be found at the base of the third ventricle in the brain (in a region called the hypothalamus). This area controls most anterior pituitary cells and thereby regulates functions in the entire body, like responses to stress, cold, sleep, and the reproductive system. The neurons send processes to a region connecting to the pituitary stalk and releasing hormones are delivered into the bloodstream. They are carried by
Pituitary stalk tract. It has been thought that the pituitary stalk may become compressed due to suprasellar tumors in the pars tuberalis region, and that the resulting compression may cause hyperprolactinemia. This phenomenon has been described as the stalk effect or pituitary stalk compression syndrome. However, at least one article suggests that the increase in prolactin in these cases may instead be caused by the tumor's secretion of preprotachykinin A-derived tachykinins, substance P, and/or neurokinin A. Damage to the pituitary stalk blocks the release of antidiuretic hormone, resulting in polydypsia (abusive water intake) and polyuria (excessive urination). Pituitary stalk The pituitary stalk