title: Exposure to light-at-night increases the growth of DMBA-induced mammary adenocarcinomas in rats.
abstract: In order to assess whether light exposure at night influences the growth of mammary tumors, as well as the role of melatonin in this process, female rats bearing DMBA-induced mammary adenocarcinomas were exposed to different lighting environments. Animals exposed to light-at-night, especially those under a constant dim light during the darkness phase, showed: (a) significantly higher rates of tumor growth as well as lower survival than controls, (b) higher concentration of serum estradiol, and (c) lower nocturnal excretion of 6-sulfatoxymelatonin, without there being differences between nocturnal and diurnal levels. These results suggest that circadian and endocrine disruption induced by light pollution, could induce the growth of mammary tumors.
authors.affiliation: Department of Physiology and Pharmacology, School of Medicine, University of Cantabria, 39011 Santander, Spain.
authors.forename: Samuel
authors.initials: S
authors.lastname: Cos
authors.forename: Dolores
authors.initials: D
authors.lastname: Mediavilla
authors.forename: Carlos
authors.initials: C
authors.lastname: Martínez-Campa
authors.forename: Alicia
authors.initials: A
authors.lastname: González
authors.forename: Carolina
authors.initials: C
authors.lastname: Alonso-González
authors.forename: Emilio J
authors.initials: EJ
authors.lastname: Sánchez-Barceló
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene; D000230:Adenocarcinoma / Q000139:chemically induced* / Q000473:pathology; D000818:Animals; D001835:Body Weight; D002940:Circadian Rhythm; D003624:Darkness; D004958:Estradiol / Q000097:blood; D004971:Estrus; D005260:Female; D008027:Light; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced* / Q000401:mortality / Q000473:pathology; D008550:Melatonin / Q000031:analogs & derivatives / Q000652:urine; D051381:Rats; D017207:Rats, Sprague-Dawley; D015996:Survival Rate
chemical_list: C054513:6-sulfatoxymelatonin; D004958:Estradiol; D015127:9,10-Dimethyl-1,2-benzanthracene; D008550:Melatonin