Effects of ionizing radiation (neutrons/gamma rays) on plasma lipids and lipoproteins in rats.
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.
Feurgard
C
C
Institut de Protection et de Sûreté Nucléaire, Département de Protection de la santé de l'Homme et de Dosimétrie, IPSN, Fontenay-aux-Roses, France.
Bayle
D
D
Guézingar
F
F
Sérougne
C
C
Mazur
A
A
Lutton
C
C
Aigueperse
J
J
Gourmelon
P
P
Mathé
D
D
D000818:Animals; D001835:Body Weight / Q000528:radiation effects; D002784:Cholesterol / Q000097:blood; D004435:Eating / Q000528:radiation effects; D005720:Gamma Rays; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D015227:Lipid Peroxidation / Q000528:radiation effects; D008055:Lipids / Q000097:blood* / Q000528:radiation effects*; D008074:Lipoproteins / Q000096:biosynthesis* / Q000528:radiation effects*; D008099:Liver / Q000378:metabolism / Q000528:radiation effects; D008297:Male; D009502:Neutrons; D051381:Rats; D017208:Rats, Wistar; D018110:Receptors, Lipoprotein / Q000378:metabolism; D014810:Vitamin E / Q000097:blood; D014916:Whole-Body Irradiation
D008055:Lipids; D008074:Lipoproteins; D018110:Receptors, Lipoprotein; C032531:apolipoprotein B,E receptor; D014810:Vitamin E; D002784:Cholesterol; D006903:Hydroxymethylglutaryl CoA Reductases