title: Protein deficiency and excess lipid synergistically augmented lipid peroxidation in growing rats.
abstract: The influence of dietary protein and lipid on superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH) and tissue lipid peroxidation, as measured by thiobarbituric acid-reactive substances (TBARS), was investigated in post-weaning male Wistar rats, fed either a diet containing 5% or 20% corn oil with 5%, 10% or 20% soy protein isolate (SPI) for four weeks. TBARS concentrations in 5% corn oil group was highest in 5% SPI group for all organs, followed by 10 and 20% SPI groups in the liver and 10 and 20% SPI groups in other organs. High lipid diet significantly increased TBARS formation in the liver of 10% SPI group. The liver and kidney SOD and GPx activities were higher in 5% and 10% SPI groups than in 20% SPI group, suggesting an augmented formation of radical substrates for these enzymes in low protein groups. Organ GSH concentrations did not show a linear correlation with dietary protein level. These results suggest that protein deficiency along with high lipid intake accelerates the peroxidative damage of the tissues by increasing oxy-radical formations and/or decreasing the defense mechanism.
authors.affiliation: Department of Nutrition, School of Medicine, University of Tokushima, Japan.
authors.forename: E J
authors.initials: EJ
authors.lastname: Sambuichi
authors.forename: A
authors.initials: A
authors.lastname: Lai
authors.forename: Y
authors.initials: Y
authors.lastname: Kido
authors.forename: F
authors.initials: F
authors.lastname: Shizuka
authors.forename: K
authors.initials: K
authors.lastname: Kishi
mesh_terms: D000818:Animals; D001798:Blood Proteins / Q000378:metabolism; D001835:Body Weight; D001921:Brain / Q000378:metabolism; D004041:Dietary Fats; D004044:Dietary Proteins; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006454:Hemoglobins / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000378:metabolism; D008297:Male; D011502:Protein-Energy Malnutrition / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis
chemical_list: D001798:Blood Proteins; D004041:Dietary Fats; D004044:Dietary Proteins; D006454:Hemoglobins; D017392:Thiobarbituric Acid Reactive Substances; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione