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Radiation effects on soluble metabolites in cultured HeLa cells examined by 1 H MRS: Changes in concentration of glutathione and of lipid catabolites induced by gamma rays and proton beams
Author(s) -
Grande Sveva,
Luciani Anna Maria,
Rosi Antonella,
Cherubini Roberto,
Conzato Mariangela,
Guidoni Laura,
Viti Vincenza
Publication year - 2001
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.10345
Subject(s) - irradiation , glutathione , proton , chemistry , hela , choline , biochemistry , in vitro , enzyme , physics , quantum mechanics , nuclear physics
Cultured HeLa cells were irradiated with a single acute dose of either gamma rays (40 Gy) or low‐energy proton beams (20 Gy). 1 H magnetic resonance spectra of intact cells harvested at different times after irradiation and of the correspondent perchloric acid (PCA) extracts prepared at different times after irradiation were run. Selected signals from glutathione and lactate were examined with the aim of investigating effects of irradiation on antioxidative stores and on mitochondrial activity. An increase of signal intensity of glutathione (GSH) takes place at 15 and 24 hr after irradiation, while a decrease of its signal intensity, accompanied by an increase of that of free glutamate, starts appearing 48 hr after irradiation. Lactate signal increases 48 hr after irradiation. Signals from lipid catabolites were also examined to explore their sensitivity in predicting the response to radiotherapy. Intensity ratios of signals of glycerophosphorylcholine and choline to that of phosphorylcholine increase with time after irradiation. Irradiating cells with gamma rays or proton beams at half a dose produces effects comparable to the metabolic variations presented here. The present experiments allow more insight into the complex pattern of the changes of GSH by irradiation and indicate that magnetic resonance spectroscopy signals from GSH, glutamate, lactate, and lipid catabolites are affected by irradiation. Finally, these data represent a first indication that the relative biological efficiency for some metabolic damage of low‐energy proton beams with respect to gamma rays can reach a value of 2. © 2002 Wiley‐Liss, Inc.