title: Relevance of pituitary aromatase and estradiol on the maintenance of the population of prolactin-positive cells in male mice.
abstract: In previous studies we demonstrated the expression of aromatase in pituitary cells. This expression is gender related, and is also associated with the presence of prolactinomas. To ascertain the relevance of aromatase in modulating the populations of prolactin-positive pituitary cells an immunocytochemical and morphometric study of prolactin-positive pituitary cells was carried out using the pituitary glands of adult male and female aromatase-knockout (ArKO) mice. Additionally has been determined if pituitary aromatase is involved in a gender-linked differentiated regulation of the prolactin-producing pituitary cells. Compared to wild-type mice, the knockout animals of both genders showed a significant decrease (p<0.01) in the cellular and nuclear areas of their prolactin cells, as well as in the percentages of the prolactin-positive cells and the proliferating prolactin cells. Our results suggest that estradiol is responsible for the maintenance of the population of prolactin cell in males and, so as not to disturb the endocrine reproductive environment, estradiol is synthesized inside the pituitary by circulating testosterone via means of aromatase P450, which acts in paracrine way. This new role for pituitary aromatase may well explain the previous findings establishing that the pituitary expression of aromatase is higher in males than in females, and the association between the development of prolactinomas and the increased expression of aromatase in tumours.
authors.affiliation: Laboratory of Neuroendocrinology of the Institute for Neuroscience of Castilla & Leon, and Laboratory of Neuroendocrinology and Obesity of the Institute of Biomedical Research of Salamanca, University of Salamanca, Spain; Department of Physiology and Pharmacology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: García-Barrado
authors.affiliation: Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain; Laboratory of Neuroendocrinology of the Institute for Neuroscience of Castilla & Leon, and Laboratory of Neuroendocrinology and Obesity of the Institute of Biomedical Research of Salamanca, University of Salamanca, Spain.
authors.forename: Enrique J
authors.initials: EJ
authors.lastname: Blanco
authors.affiliation: Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Catalano-Iniesta
authors.affiliation: Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Sanchez-Robledo
authors.affiliation: Laboratory of Neuroendocrinology of the Institute for Neuroscience of Castilla & Leon, and Laboratory of Neuroendocrinology and Obesity of the Institute of Biomedical Research of Salamanca, University of Salamanca, Spain; Department of Physiology and Pharmacology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: María Carmen
authors.initials: MC
authors.lastname: Iglesias-Osma
authors.affiliation: Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Carretero-Hernández
authors.affiliation: Laboratory of Neuroendocrinology of the Institute for Neuroscience of Castilla & Leon, and Laboratory of Neuroendocrinology and Obesity of the Institute of Biomedical Research of Salamanca, University of Salamanca, Spain; Department of Physiology and Pharmacology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Rodríguez-Cobos
authors.affiliation: Laboratory of Molecular Neuroendocrinology, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.
authors.forename: Deborah Jane
authors.initials: DJ
authors.lastname: Burks
authors.affiliation: Department of Human Anatomy and Histology, Faculty of Medicine, University of Salamanca, Spain; Laboratory of Neuroendocrinology of the Institute for Neuroscience of Castilla & Leon, and Laboratory of Neuroendocrinology and Obesity of the Institute of Biomedical Research of Salamanca, University of Salamanca, Spain. Electronic address: jcar@usal.es.
authors.forename: José
authors.initials: J
authors.lastname: Carretero
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism*; D049109:Cell Proliferation / Q000235:genetics / Q000502:physiology; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010902:Pituitary Gland / Q000201:enzymology* / Q000378:metabolism*; D011388:Prolactin / Q000378:metabolism*; D012737:Sex Factors; D013739:Testosterone / Q000378:metabolism
chemical_list: D013739:Testosterone; D004958:Estradiol; D011388:Prolactin; D001141:Aromatase
keywords: Aromatase; Cell proliferation; Estradiol; Immunocytochemistry; Pituitary; Prolactin