Electron spin resonance studies of free radicals in gamma-irradiated golden hamster embryo cells: radical formation at 77 and 295 K, and radioprotective effects of vitamin C at 295 K

• Published in: Radiation research Vol. 136; no. 3; p. 361
• Main Authors: Yoshimura, T, Matsuno, K, Miyazaki, T, Suzuki, K, Watanabe, M
• Format: Journal Article
• Language: English
• Published: United States 01.12.1993
• Subjects: Animals; Ascorbic Acid - pharmacology; Cell Line; Cricetinae; Dimethyl Sulfoxide - pharmacology; Dose-Response Relationship, Radiation; Electron Spin Resonance Spectroscopy; Embryo, Mammalian - chemistry; Embryo, Mammalian - drug effects; Embryo, Mammalian - radiation effects; Free Radicals; Gamma Rays; Mesocricetus; Radiation-Protective Agents - pharmacology; Temperature
• ISSN: 0033-7587
• DOI: 10.2307/3578548

Formation of free radicals in golden hamster embryo (GHE) cells produced by gamma irradiation at 77 and 295 K has been studied by electron spin resonance (ESR) spectroscopy. The yields of free radicals in the gamma-irradiated frozen cells at 77 K increase linearly with increasing dose in the range from 8 Gy to 1.3 kGy, suggesting that the mechanism of radical formation at a dose of 8 Gy is the same as that at 1.3 kGy. When GHE cells are irradiated with 5 kGy gamma rays at 295 K and then the ESR spectrum is measured at 77 K, a part of the organic radicals produced can be observed clearly. The organic radicals survive in GHE cells for more than 24 h at room temperature. The formation of the organic radicals by gamma irradiation is suppressed upon the addition of vitamin C to the GHE cells. When an aqueous solution of albumin (0.1 kg dm-3) is gamma-irradiated with 5 kGy at 295 K, albumin radicals are observed by ESR. The formation of the albumin radicals is suppressed drastically upon the addition of vitamin C. The efficient radioprotection of vitamin C against radical formation has been interpreted in terms of the scavenging of albumin radicals by vitamin C.