title: Pineal gland function is required for colon antipreneoplastic effects of physical exercise in rats.
abstract: Light-at-night exposure enhances the risk of cancer. Colon cancer is among the most dangerous tumors affecting humankind. Physical exercise has shown positive effects against colon cancer. Here, we investigated whether pineal gland modulates antipreneoplastic effects of physical exercise in the colon. Surgical and non-surgical pineal impairments were performed to clarify the relationship between the pineal gland activity and manifestation of colonic preneoplastic lesions. Next, a progressive swimming training was applied in rats exposed or not to either non-surgical pineal impairment or carcinogen treatment for 10 weeks. Both surgical and non-surgical pineal impairments increased the development of colon preneoplasia. It was further found that impairing the pineal gland function, higher rates of DNA damage were induced in colonic epithelial and enteric glial cells. Physical exercise acted positively against preneoplasia, whereas impairing the pineal function with constant light exposure disrupts its positive effects on the development of preneoplastic lesions in the colon. This was yet related to increased DNA damage in glial cells and enteric neuronal activation aside from serum melatonin levels. Our findings suggest that protective effects of physical exercise against colon cancer are dependent on the pineal gland activity.
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: F T T
authors.initials: FT
authors.lastname: Frajacomo
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: W
authors.initials: W
authors.lastname: de Paula Garcia
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: C R
authors.initials: CR
authors.lastname: Fernandes
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: S B
authors.initials: SB
authors.lastname: Garcia
authors.affiliation: Department of Pathology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: V
authors.initials: V
authors.lastname: Kannen
mesh_terms: D019813:1,2-Dimethylhydrazine; D000818:Animals; D003110:Colonic Neoplasms / Q000517:prevention & control*; D051546:Cyclooxygenase 2 / Q000032:analysis; D004247:DNA / Q000032:analysis*; D004249:DNA Damage / Q000502:physiology; D017615:Enteric Nervous System / Q000502:physiology; D008027:Light / Q000009:adverse effects; D008297:Male; D008550:Melatonin / Q000097:blood; D008668:Metallothionein / Q000032:analysis; D009457:Neuroglia / Q000737:chemistry; D009474:Neurons / Q000737:chemistry; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010870:Pineal Gland / Q000502:physiology* / Q000601:surgery; D011230:Precancerous Conditions / Q000139:chemically induced / Q000737:chemistry / Q000473:pathology / Q000517:prevention & control*; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D004247:DNA; D008668:Metallothionein; D051546:Cyclooxygenase 2; C489691:Ptgs2 protein, rat; D019813:1,2-Dimethylhydrazine; D008550:Melatonin
keywords: Dysplasia; carcinogenesis; colon tissue; physical training