title: Degree of protein deficiency affects the extent of the depression of the antioxidative enzyme activities and the enhancement of tissue lipid peroxidation in rats.
abstract: To investigate the effects of various dietary protein levels on tissue lipid peroxidation and antioxidative enzyme activities, four groups of Long-Evans male weanling rats were fed a 6, 8, 12 or 20% lactalbumin diet for 6 wk. The red blood cell in vitro spontaneous hemolysis values were 28.6, 24.9, 18.9 and 14.1% for the rats fed the 6, 8, 12 and 20% lactalbumin diets, respectively. The thiobarbituric acid-reactive substances (TBARS) in plasma, RBC, liver, kidney, muscle, lung, spleen and heart were lowest in the group fed the 20% lactalbumin diet. Rats fed the diet containing 12% lactalbumin had significantly greater TBARS in plasma, spleen, kidney and muscle compared with rats fed the 20% lactalbumin diet. Rats fed the 8% lactalbumin diet had markedly higher TBARS levels (P < 0.05) in all tissues examined than did those fed the 12% lactalbumin diet. The TBARS in all eight tissues of the rats fed the 6% lactalbumin diet were even higher than those of rats fed the 8% lactalbumin diet (P < 0.05). The activities of glutathione peroxidase, superoxide dismutase and glucose-6-phosphate dehydrogenase in RBC were gradually lowered (P < 0.05) when the dietary protein level was decreased stepwise. The activities of these antioxidative enzymes in liver also were reduced significantly when dietary protein level decreased from 20 to 12% and then to 8%. These enzyme activities in the rats fed the diet containing 6% lactalbumin generally were not different from those of the rats fed 8% lactalbumin.(ABSTRACT TRUNCATED AT 250 WORDS)
authors: Department of Agricultural Chemistry, National Taiwan University, Taipei, Republic of China.
authors: C J
authors: CJ
authors: Huang
authors: M L
authors: ML
authors: Fwu
mesh_terms: D000818:Animals; D004044:Dietary Proteins / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology / Q000378:metabolism*; D005954:Glucosephosphate Dehydrogenase / Q000032:analysis*; D005979:Glutathione Peroxidase / Q000378:metabolism; D015227:Lipid Peroxidation / Q000502:physiology*; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D009752:Nutritional Status; D010084:Oxidation-Reduction; D011488:Protein Deficiency / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
chemical_list: D004044:Dietary Proteins; D017392:Thiobarbituric Acid Reactive Substances; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase