Relationship Between Calorie Restriction, Lipid Peroxidation, Gluthathione Peroxidase And Gluthathione In Aged Rats
AbstractGlutathione peroxidase activity, lipid peroxidation and the glutathione system were assayed in the lungs, kidneys and brains of 18 month old rats (n=12), who had been on 60% of the caloric intake of the ad-libitum fed rats since 6 weeks of age and also in the control age group of rats (n=12) that were fed ad-libitum.
Lipid peroxidation was markedly lower in the plasma of the caloric restricted group from 16.23+1.53 nmol MDA/ml in the ad-libitum group to 10.34+0.78 nmol MDA/ml (p<0.002). Similarly lipid peroxidation was lower in the lungs (p<0.0001) and the brain (p<0.02) while it was higher in the kidney (p<0.0001) when compare3d with the ad-libitum fed rats.
The activity of glutathione peroxidase was higher in the lungs and brain of the caloric restricted rats by 44.4% (p<0.024) and 40% (p<0.36) respectively, whereas it was lower in the kidneys of the caloric restricted group by 38% (p<0.01) when compared to the ad-libitum fed rats.
Glutathione system assayed by measuring the total glutathione (tGHS) and GSSG/GSH% were computed. Total GSH, GSSG and GSH were significantly higher in the lungs while there was little difference in the GSSG/GSH% ratio. On the other hand, the tGSH, GSSG and GSH reduced in the kidney during caloric restriction and there was no difference in the GSSG/GSH% ratio between the two groups. In the brain of the caloric restricted rats, there was little or no change in the tGSH and GSH, although the GSSG and GSSG/GSH% ratio were increased significantly. These results suggest that aging of rats had been decelerated by caloric restriction due to the decrease in the peroxidative damage in the lungs and brain.
Key Words: Food Restriction, Lipid Peroxidation, Aging, Glutathione, Free Radicals
[J. of Med. & Medical Sci. Vol.1(1) 1999: 14-19]