Effects of ionizing radiation (neutrons/gamma rays) on plasma lipids and lipoproteins in rats

• Published in: Radiation research Vol. 150; no. 1; p. 43
• Main Authors: Feurgard, C, Bayle, D, Guézingar, F, Sérougne, C, Mazur, A, Lutton, C, Aigueperse, J, Gourmelon, P, Mathé, D
• Format: Journal Article
• Language: English
• Published: United States 01.07.1998
• Subjects: Animals; Body Weight - radiation effects; Cholesterol - blood; Eating - radiation effects; Gamma Rays; Hydroxymethylglutaryl CoA Reductases - metabolism; Lipid Peroxidation - radiation effects; Lipids - blood; Lipids - radiation effects; Lipoproteins - biosynthesis; Lipoproteins - radiation effects; Liver - metabolism; Liver - radiation effects; Male; Neutrons; Rats; Rats, Wistar; Receptors, Lipoprotein - metabolism; Vitamin E - blood; Whole-Body Irradiation
• ISSN: 0033-7587
• DOI: 10.2307/3579644

Male Wistar rats weighing 250 g were exposed to 4 Gy of neutrons/gamma radiation (3.33 Gy of neutrons and 0.66 Gy of gamma rays). After whole-body irradiation, plasma cholesterol and phospholipid levels increased up to 62 and 37%, respectively, at day 4 and then returned to control values 12 days after irradiation. Plasma triglyceride concentrations decreased concomitantly with decreased food intake after irradiation but remained higher than in pair-fed control rats. Plasma lipoproteins were separated by ultracentrifugation on a density gradient (1.006-1.210 g/ml). Four days after irradiation, most of the cholesterol (62% compared to 31% in controls, P < 0.001) is transported by apolipoprotein E-rich high-density lipoproteins. At the same time, plasma levels of apolipoproteins B and E were increased by 28 and 65%, respectively, while those of apolipoproteins AI and AIV were reduced by 21 and 59%, respectively. While in the liver of irradiated rats the apolipoprotein B/E receptor number was not modified, the hydroxymethylglutaryl coenzyme A reductase activity was fivefold higher than in control pair-fed rats. Four days after irradiation, the susceptibility of lipoproteins to peroxidation, as measured by the formation of conjugated dienes in the presence of Cu2+, was markedly increased while plasma vitamin E levels were decreased, demonstrating that irradiation reduces antioxidant stores markedly. These results suggest that such modified lipoproteins could be involved in radiation-induced vascular damage.