Regular exercise reduces colon tumorigenesis associated with suppression of iNOS
| Autor: | Toshikazu Yoshikawa, Wataru Aoi, Liu Po Hung, Hiroshi Ichikawa, Yuko Tanimura, Yukari Kawai, Tomohisa Takagi, Satoshi Kokura, Katsura Mizushima, Ryota Koyama, Y. Takanami, Yuji Naito |
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| Rok vydání: | 2010 |
| Předmět: |
Male
medicine.medical_specialty Antioxidant Colorectal cancer medicine.medical_treatment Azoxymethane Biophysics Nitric Oxide Synthase Type II Citrate (si)-Synthase medicine.disease_cause Biochemistry Mice chemistry.chemical_compound Physical Conditioning Animal Internal medicine otorhinolaryngologic diseases medicine Animals Molecular Biology chemistry.chemical_classification Mice Inbred BALB C biology Tumor Necrosis Factor-alpha business.industry Nitrotyrosine Body Weight Cell Biology medicine.disease Nitric oxide synthase Cell Transformation Neoplastic Endocrinology Enzyme chemistry Cyclooxygenase 2 Colonic Neoplasms biology.protein Tumor necrosis factor alpha business Carcinogenesis Aberrant crypt foci |
| Zdroj: | Biochemical and Biophysical Research Communications. 399:14-19 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/j.bbrc.2010.07.023 |
| Popis: | Several epidemiological studies have shown that regular exercise can prevent the onset of colon cancer, although the mechanism involved is unclear. Expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) is often elevated in an initial step of tumorigenesis and promotes colorectal cancer. We investigated the effect of exercise on colon tumorigenesis associated with iNOS and COX-2 in azoxymethan (AOM)-injected mice. Balb/c mice (8 weeks old) were divided into three groups of 20 animals each, consisting of a sedentary control group, an AOM group, and an exercise plus AOM group. Mice in the groups receiving AOM were injected intraperitoneally with AOM weekly for 2 weeks. Six weeks of regular exercise suppressed the generation of aberrant crypt foci (ACF) in the colon by AOM. Expression of iNOS was decreased by exercise compared with that in sedentary mice along with lower nitrotyrosine level while COX-2 was not changed by either AOM or exercise. Additionally, tumor necrosis factor alpha (TNFalpha) was decreased by exercise in the colon and plasma. There was no effect of exercise on the expression of antioxidant enzymes and chaperon protein in the colon. Our results suggest that regular exercise prevents colon tumorigenesis, at least partly via the suppression of iNOS expression associated with anti-inflammation. |
| Databáze: | OpenAIRE |
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