Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/200011
Type: Artigo de periódico
Title: Uncoupling Endothelial Nitric Oxide Synthase Is Ameliorated By Green Tea In Experimental Diabetes By Re-establishing Tetrahydrobiopterin Levels.
Author: Faria, Aline M
Papadimitriou, Alexandros
Silva, Kamila C
Lopes de Faria, Jacqueline M
Lopes de Faria, José B
Abstract: The current study investigated the potential of green tea (GT) to improve uncoupling of endothelial nitric oxide synthase (eNOS) in diabetic conditions. In rats with streptozotocin-induced diabetes, nitric oxide (NO) bioavailability was reduced by uncoupling eNOS, characterized by a reduction in tetrahydrobiopterin (BH(4)) levels and a decrease in the eNOS dimer-to-monomer ratio. GT treatment ameliorated these abnormalities. Moreover, immortalized human mesangial cells (ihMCs) exposed to high glucose (HG) levels exhibited a rise in reactive oxygen species (ROS) and a decline in NO levels, which were reversed with GT. BH(4) and the activity of guanosine triphosphate cyclohydrolase I decreased in ihMCs exposed to HG and was normalized by GT. Exogenous administration of BH(4) in ihMCs reversed the HG-induced rise in ROS and the decline in NO production. However, coadministration of GT with BH(4) did not result in a further reduction in ROS production, suggesting that reduced ROS with GT was indeed secondary to uncoupled eNOS. In summary, GT reversed the diabetes-induced reduction of BH(4) levels, ameliorating uncoupling eNOS, and thus increasing NO bioavailability and reducing oxidative stress, two abnormalities that are involved in the pathogenesis of diabetic nephropathy.
Subject: Animals
Antioxidants
Biopterin
Camellia Sinensis
Cells, Cultured
Diabetes Mellitus, Experimental
Gtp Cyclohydrolase
Humans
Mesangial Cells
Nitric Oxide
Nitric Oxide Synthase Type Iii
Oxidative Stress
Rats
Rats, Inbred Shr
Reactive Oxygen Species
Tea
Rights: fechado
Identifier DOI: 10.2337/db11-1241
Address: http://www.ncbi.nlm.nih.gov/pubmed/22586583
Date Issue: 2012
Appears in Collections:Unicamp - Artigos e Outros Documentos

Files in This Item:
File SizeFormat 
pmed_22586583.pdf1.63 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.