ABSTRACT
A modification of the Asakawa-Matsushita iodometric assay method for the determination of the content of lipid hydroperoxides was developed which permits the simultaneous processing of many samples of high lipid content. The method has the advantages of simplicity as well as good reproducibility, so it is not necessary to process standards with each determination. Our technique exceeds the sensitivity attained with other spectrophotometric determinations reported in the literature. The method requires the total elimination of water from the samples, and this was accomplished using an azeotropic mixture of ethanol:water of 96:4. The results obtained with liposomes indicate that the method is applicable to biological material limited to small volume samples, ranging 5-50 microliters. We want to emphasize that this method permits the study of the peroxidation process as function of time.
Subject(s)
Hydrogen Peroxide/analysis , Liposomes/chemistry , Spectrophotometry/methods , Lipids/chemistry , Phosphatidylcholines/chemistryABSTRACT
A study of oxidative damage was made in elderly noninsulin-dependent diabetes mellitus (NIDDM) patients. A statistically significant increase in glucose and fructosamine was found in fasting NIDDM patients, as well as an increase in the oxidation induced by tert-butyl hydroperoxide. The Total Reactive Antioxidant Potential (TRAP) of the plasma was much reduced (p < .02) and the uricemia was unchanged. The erythrocytes of diabetic patients show greater basal oxidation products (p < .05), and the susceptibility of the diabetic erythrocytes to oxidation injury was also shown to increase in the oxidation induced by t-BOOH (p < .05). Linear regression studies showed that TRAP was associated directly with uric acid (p < .05) and inversely with fructosamine and with glucose (p < .03 and p < .05 respectively) in patients with NIDDM, but not in the controls. The levels of fructosamine were found to be related to the basal damage of the red blood cells (direct correlation, p < .001). This study suggest an useful approach to diabetic oxidative stress for clinical settings.
Subject(s)
Antioxidants/metabolism , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Oxidative Stress , Adult , Aged , Erythrocytes/metabolism , Fasting , Fructosamine/blood , Humans , Lipid Peroxidation , Lipids/blood , Male , Middle Aged , Peroxides/pharmacology , Uric Acid/blood , tert-ButylhydroperoxideABSTRACT
In order to investigate the implications of oxidative disturbances in the hemolysis associated with the Hemolytic Uremic Syndrome (HUS), basal levels of lipid peroxidation products, the response to t-butyl hydroperoxide induced damage and membrane fluidity were assayed by the technique of electron spin resonance in erythrocytes spin labeled with 5-Doxyl stearic acid obtained from eight children with HUS, during the 1st, 2nd, 4th and 12th weeks after diagnosis. During the acute phase of the disease, red blood cells (RBC) showed increased initial lipid peroxidation products, a higher susceptibility to oxidative insult and a lower membrane fluidity. All parameters reached control values the 12th week after diagnosis. The results suggest that in the acute phase of HUS, RBCs are exposed to an oxidative imbalance that could contribute to hemolysis directly through oxidative damage and/or by decreasing membrane fluidity.
Subject(s)
Erythrocytes/metabolism , Hemolytic-Uremic Syndrome/metabolism , Membrane Fluidity , Oxidative Stress , Adolescent , Adult , Child , Female , Hemolytic-Uremic Syndrome/blood , Humans , Lipid Peroxidation , Male , Peroxides/pharmacology , Reactive Oxygen Species , tert-ButylhydroperoxideSubject(s)
Gold Colloid, Radioactive , Mononuclear Phagocyte System/physiology , Phagocytosis , Animals , Gelatin , Povidone , RatsABSTRACT
Se ha estudiado la cinetica de fagocitosis de coloides de 198Au protegidos con gelatina en ratas Wistar previamente tratadas con Corynebacterium parvum (CBP), con el fin de dilucidar su mecanismo de inmunomodulacion. Para ello se utilizo la tecnica de canulacion carotideo-carotidiana y se analizaron las variaciones de la velocidad de fagocitosis, v, posteriores a la administracion de CBP, obtenidas con una dosis de coloides de 198Au menor o mayor que Ks. En el primer caso no se observaron cambios significativos de v, mientras que en el segundo se determinaron incrementos significativos de v, que se hicieron maximos a los 6 dias luego de la inyeccion de CBP. El analisis cinetico de los datos obtenidos permite deducir que la accion del CBP se ejerce en la etapa de entrada de la particula coloidal al interior de la celula reticuloendotelial
Subject(s)
Animals , Rats , Gold Radioisotopes , Phagocytosis , Propionibacterium acnesABSTRACT
Se ha estudiado la cinetica de fagocitosis de coloides de 198Au protegidos con gelatina en ratas Wistar previamente tratadas con Corynebacterium parvum (CBP), con el fin de dilucidar su mecanismo de inmunomodulacion. Para ello se utilizo la tecnica de canulacion carotideo-carotidiana y se analizaron las variaciones de la velocidad de fagocitosis, v, posteriores a la administracion de CBP, obtenidas con una dosis de coloides de 198Au menor o mayor que Ks. En el primer caso no se observaron cambios significativos de v, mientras que en el segundo se determinaron incrementos significativos de v, que se hicieron maximos a los 6 dias luego de la inyeccion de CBP. El analisis cinetico de los datos obtenidos permite deducir que la accion del CBP se ejerce en la etapa de entrada de la particula coloidal al interior de la celula reticuloendotelial