Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/195972
Type: Artigo de periódico
Title: Characterization Of The Peroxidase System At Low H2o2 Concentrations In Isolated Neonatal Rat Islets.
Author: Stoppiglia, Luiz F
Rezende, Luiz F
Ferreira, Fabiano
Filiputti, Eliane
Carneiro, Everardo M
Boschero, Antonio C
Abstract: B cell destruction during the onset of diabetes mellitus is associated with oxidative stress. In this work, we attempted to further trace the fate of H2O2 inside the pancreatic islets and determine whether it is mediated by enzymatic (peroxidase) activity or by chemical reaction with thiols from any protein chain. Our results suggest that the islet cells have a very similar peroxidase activity at the hydrophilic (cytoplasm) and hydrophobic compartments (organelles and nucleus), independent of the catalase content of the samples. This activity is composed of sacrificial thiols and by proteins with Fe3+/Mn3+ ions at non-heme catalytic sites. The capacity of the hydrophobic fraction to scavenge O2- was increased in the presence of high concentrations of NADP* and RS* and was highly dependent on RSH. On the contrary, the hydrophilic fraction exhibited a low RSH-dependent activity where the O2- scavenging is related to metal Cu2+/Fe3+/Mn3+ ions attached to the protein molecules.
Subject: Animals
Animals, Newborn
Catalase
Catalytic Domain
Cell Nucleus
Cells, Cultured
Copper
Cytoplasm
Dose-response Relationship, Drug
Heme
Hydrogen Peroxide
Ions
Iron
Islets Of Langerhans
Kinetics
Magnesium
Models, Chemical
Nadp
Oxidation-reduction
Oxidative Stress
Oxygen
Peroxidase
Rats
Sulfhydryl Compounds
Superoxides
Time Factors
Rights: fechado
Identifier DOI: 10.1016/j.bbadis.2004.06.005
Address: http://www.ncbi.nlm.nih.gov/pubmed/15469905
Date Issue: 2004
Appears in Collections:Unicamp - Artigos e Outros Documentos

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