Rethinking the stalk effect: a new hypothesis explaining suprasellar tumor-induced hyperprolactinemia.
The pars tuberalis is a distinct subdivision of the pituitary gland but its function remains poorly understood. Suprasellar tumors in this pars tuberalis region are frequently accompanied by hyperprolactinemia. As these tumors do not immunoreact for any of the established pituitary hormones, they are classified as nonsecretory. It has been postulated that these suprasellar tumors induce hyperprolactinemia by compressing the pituitary stalk, resulting in impaired dopamine delivery to the pituitary and, consequently, disinhibition of the lactotropes. An alternative hypothesis proposed is that suprasellar tumors secrete a specific pars tuberalis factor that stimulates prolactin secretion. Hypothesized candidates are the preprotachykinin A derived tachykinins, substance P and/or neurokinin A.
Skinner
Donal C
DC
Department of Zoology, Physiology and Neurobiology Program, University of Wyoming, Dept. 3166, 1000 E University Avenue, Laramie, WY 82071, USA. dcs@uwyo.edu
D000818:Animals; D020863:Central Nervous System Cysts / Q000150:complications* / Q000378:metabolism*; D006801:Humans; D006966:Hyperprolactinemia / Q000209:etiology* / Q000378:metabolism*; D008954:Models, Biological; D010902:Pituitary Gland / Q000378:metabolism*; D010911:Pituitary Neoplasms / Q000150:complications* / Q000378:metabolism*