title: Effect of aging on the expression of BDNF and TrkB isoforms in rat pituitary.
abstract: Brain-derived neurotrophic factor (BDNF) is a key regulator of neuronal plasticity in adult rat brain and its effects are mediated through TrkB receptors. BDNF and its receptors are also localized in the pituitary, but their expressions throughout the rat lifespan are poorly known. Here we analyzed levels of BDNF and the different subtypes of TrkB receptors (mRNA and proteins) in the rat pituitary at different stages of life. BDNF immunoreactivity was expressed in folliculo-stellate cells from the anterior pituitary and in the intermediate lobe. TrkB.FL and TrkB.T1 receptors were strongly and essentially expressed in the intermediate lobe similar to the alpha-MSH localization pattern. These receptors begun decreasing at middle-age but TrkB.T2 was not detected in the pituitary at any age. Finally, in vitro alpha-MSH release from the intermediate lobe was correlated with the receptor content throughout the lifespan. The present results demonstrate the presence of BDNF in folliculo-stellate cells and indicated that receptors, rather than BDNF itself, are impaired with aging. These changes can contribute to explain age-dependent endocrine changes.
authors.affiliation: IGMM, UMR5535 CNRS, Montpellier Cedex 5, France. florence.rage@igmm.cnrs.fr
authors.forename: Florence
authors.initials: F
authors.lastname: Rage
authors.forename: Michèle
authors.initials: M
authors.lastname: Silhol
authors.forename: Fabien
authors.initials: F
authors.lastname: Binamé
authors.forename: Sandor
authors.initials: S
authors.lastname: Arancibia
authors.forename: Lucia
authors.initials: L
authors.lastname: Tapia-Arancibia
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D010902:Pituitary Gland / Q000378:metabolism*; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020033:Protein Isoforms; D020813:Receptor, trkB