title: Ontogenetic development, sexual differentiation, and effects of Aroclor 1254 exposure on expression of the arylhydrocarbon receptor and of the arylhydrocarbon receptor nuclear translocator in the rat hypothalamus.
abstract: Interaction of polychlorinated biphenyls (PCBs) with the aryl hydrocarbon receptor (AhR)/nuclear translocator (ARNT) system might interfere with the mechanisms controlling the sexual differentiation of the developing hypothalamus. The aim of this study was to evaluate the presence of AhR/ARNT in brain cells and the developmental profile of their expression in the hypothalamus of male and female rats during the perinatal period. Brain accumulation of the main PCB congeners after prenatal exposure to Aroclor 1254 and its influence on hypothalamic expression of AhR/ARNT was also assessed. The results show that: (a) AhR and ARNT are expressed both in neurons and in glia; (b) AhR expression progressively increases in the developing hypothalamus particularly in males, while ARNT is relatively constant in both sexes; (c) the prenatal administration of Aroclor to dams produces a differential accumulation of PCBs, depending on the chlorine atom number, and stimulates AhR expression only in the male hypothalamus. In conclusion, the developing male hypothalamus might be more sensitive to disrupting potential of PCBs.
authors.affiliation: Department of Endocrinology, University of Milano, Via Balzaretti, 9, 20133 Milano, Italy.
authors.forename: Antonia
authors.initials: A
authors.lastname: Pravettoni
authors.forename: Alessandra
authors.initials: A
authors.lastname: Colciago
authors.forename: Paola
authors.initials: P
authors.lastname: Negri-Cesi
authors.forename: Sara
authors.initials: S
authors.lastname: Villa
authors.forename: Fabio
authors.initials: F
authors.lastname: Celotti
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator / Q000096:biosynthesis / Q000378:metabolism*; D002478:Cells, Cultured; D020111:Chlorodiphenyl (54% Chlorine) / Q000008:administration & dosage / Q000633:toxicity*; D005260:Female; D005865:Gestational Age; D007031:Hypothalamus / Q000187:drug effects* / Q000196:embryology / Q000378:metabolism; D008297:Male; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D018336:Receptors, Aryl Hydrocarbon / Q000096:biosynthesis / Q000378:metabolism*; D012733:Sex Differentiation / Q000187:drug effects*; D012737:Sex Factors
chemical_list: D018336:Receptors, Aryl Hydrocarbon; D020111:Chlorodiphenyl (54% Chlorine); D051784:Aryl Hydrocarbon Receptor Nuclear Translocator