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Title: Effect of in vivo heart irradiation on the development of antioxidant defenses and cardiac functions in the rat

During radiotherapy of thoracic tumors, the heart is often included in the primary treatment volume, and chronic impairment of myocardial function occurs. The cellular biomolecules are altered directly by radiation or damaged indirectly by free radical production. The purpose of this investigation was to evaluate the biochemical and functional response of the rat heart to a single high dose of radiation. The effect of 20 Gy local X irradiation was determined in the heart of Wistar rats under general anesthesia. Mechanical performances were measured in vitro using an isolated perfused working heart model, and cardiac antioxidant defenses were also evaluated. Hearts were studied at 1 and 4 months after irradiation. This single dose of radiation induced a marked drop in the mechanical activity of the rat heart: aortic output was significantly reduced (18% less than control values) at 1 month postirradiation and remained depressed for the rest of the experimental period (21% less than control 4 months after treatment). This suggests the development of myocardial failure after irradiation. The decline of functional parameters was associated with changes in antioxidant defenses. The decrease in cardiac levels of vitamin E (-30%) was associated with an increase in the levels of Mn-SOD andmore » glustathione peroxidase (+45.5% and +32%, respectively, at 4 months postirradiation). However, cardiac vitamin C and catalase levels remained constant. Since these antioxidant defenses were activated relatively long after irradiation, it is suggested that this was probable due to the production of free radical species associated with the development of inflammation. 49 refs., 8 figs., 1 tab.« less
Authors:
; ;  [1]
  1. Facultes de Medecine et de Pharmacie, Dijon (France) [and others
Publication Date:
OSTI Identifier:
160185
Resource Type:
Journal Article
Resource Relation:
Journal Name: Radiation Research; Journal Volume: 144; Journal Issue: 1; Other Information: PBD: Oct 1995
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
56 BIOLOGY AND MEDICINE, APPLIED STUDIES; 55 BIOLOGY AND MEDICINE, BASIC STUDIES; HEART; BIOLOGICAL RADIATION EFFECTS; BIOCHEMICAL REACTION KINETICS; X RADIATION; DOSE RATES; CHEST; RADIOTHERAPY; IRRADIATION; RATS; VITAMIN E; ANTIOXIDANTS