title: Ghrelin immunoexpression in the human hypophysis.
abstract: The aim of this study was to immunohistochemically localize ghrelin in autopsy-obtained, nontumoral human pituitaries. Double immunostaining was also undertaken to determine the pituitary cell type expressing both adenohypophysial hormones and ghrelin. Results showed that ghrelin is present in the adenohypophysis, its immunoexpression being cytoplasmic, weak-to-moderate, and localized to a subset of cells. Double immunostaining showed that ghrelin is present in 51% to 90% of growth hormone-producing, luteinizing-producing, and α-subunit-producing cells. Ghrelin immunoexpression was less frequently observed in other adenohypophysial cell types, being seen in 30% of adrenocorticotropin and follicle-stimulating hormones, 15% of thyrotropin, and 10% of prolactin-immunoreactive cells. Ghrelin immunopositivity was also seen in nerve fibers and Herring bodies of the neurohypophysis and pituitary stalk. More work is needed to elucidate the role of ghrelin in adenohypophysial and neurohypophysial endocrine activity. It may well be that ghrelin exerts an autocrine/paracrine effect and can modulate hormone synthesis and release.
authors.affiliation: Division of Pathology, Department of Laboratory Medicine, St. Michael's Hospital, University of Toronto, Toronto, Canada. rotondof@smh.ca
authors.forename: Fabio
authors.initials: F
authors.lastname: Rotondo
authors.forename: Angelo
authors.initials: A
authors.lastname: Rotondo
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: Michael
authors.initials: M
authors.lastname: Cusimano
authors.forename: Eleanor
authors.initials: E
authors.lastname: Latta
authors.forename: Luis V
authors.initials: LV
authors.lastname: Syro
authors.forename: Kalman
authors.initials: K
authors.lastname: Kovacs
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019898:Autocrine Communication / Q000502:physiology*; D005260:Female; D005786:Gene Expression Regulation / Q000502:physiology*; D054439:Ghrelin / Q000096:biosynthesis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019899:Paracrine Communication / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000378:metabolism*; D010904:Pituitary Gland, Posterior / Q000166:cytology / Q000502:physiology*
chemical_list: D054439:Ghrelin