Nicotinamide increases thyroid radiosensitivity by stimulating nitric oxide synthase expression and the generation of organic peroxides
| Autor: | Mario A. Pisarev, M.A Dagrosa, M. Agote Robertson, G. J. Juvenal, Juan José Poderoso, P. Finochietto, C. A. Gamba, Maria Clara Franco, M. Viaggi |
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| Rok vydání: | 2006 |
| Předmět: |
Male
Niacinamide medicine.medical_specialty Endocrinology Diabetes and Metabolism Clinical Biochemistry Thyroid Gland Biochemistry Hyperthyroidism Gene Expression Regulation Enzymologic Nitric oxide Superoxide dismutase Iodine Radioisotopes chemistry.chemical_compound Endocrinology Enos Internal medicine medicine Animals Thyroid Neoplasms Rats Wistar Thyroid cancer chemistry.chemical_classification biology Nicotinamide Glutathione peroxidase Biochemistry (medical) Thyroid General Medicine biology.organism_classification medicine.disease Peroxides Rats Nitric oxide synthase medicine.anatomical_structure chemistry Vitamin B Complex biology.protein Nitric Oxide Synthase Oxidation-Reduction |
| Zdroj: | Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme. 38(1) |
| ISSN: | 0018-5043 |
| Popis: | Differentiated thyroid cancer and hyperthyroidism are treated with radioiodine. However, when the radioisotope dose exceeds certain limits, the patient must be hospitalized to avoid contact with people that would otherwise be exposed to radiation. It would be desirable to obtain a similar therapeutic effect using lower radioiodine doses. Radiosensitizers can be utilized for this purpose. Nicotinamide (NA) increases thyroid radiosensitivity to 131I in both normal and goitrous glands. NA causes a significant increase in thyroid blood flow, which would increase tissue oxygenation and tissue damage via free radicals. Wistar rats were treated with either nicotinamide (NA), 131I or both. The expression of the three isoforms of nitric oxide synthase (NOS) in the thyroid (Western blot) and the activities of SOD, GPx, catalase and organic peroxides were determined. Treatment with NA or 131I increased the expression of eNOS and the generation of organic peroxides. When administered jointly, they showed a synergistic effect. No changes were observed in the other NOS isoforms or in the activities of catalase, glutathione peroxidase and superoxide dismutase. NA potentiates the effect of 131I by increasing eNOS, which would in turn stimulate NO production, increasing thyroid blood flow and tissue damage via organic peroxides. |
| Databáze: | OpenAIRE |
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