The effect of dimerumic acid on LPS-induced downregulation of Mrp2 in the rat.
Biochem Pharmacol
; 80(4): 533-9, 2010 Aug 15.
Article
em En
| MEDLINE
| ID: mdl-20457138
ABSTRACT
Oxidative stress is known to be a common feature of cholestatic syndrome. Lipopolysaccharide (LPS) induces cholestasis, causing multidrug resistance-associated protein 2 (Mrp2) downregulation in two different ways early retrieval from the canalicular membrane and the latter event of reduced mRNA expression. However, the triggering factor for LPS-induced cholestasis is not fully understood. In this study, we examined the effect of dimerumic acid (DMA), an antioxidant and traditional Chinese medicine, on endotoxin-induced Mrp2 downregulation in rat liver. At 3h following LPS injection (4mg/kg body weight), canalicular Mrp2 localization was disrupted without changing the expression of Mrp2 protein or the integrity of tight junctions in the liver. Pretreatment with DMA (12mg/kg body weight) counteracted LPS-induced subcellular distribution, and decreased the bile flow rate and biliary glutathione (GSH) excretion. At 12h following LPS injection, Mrp2 protein and mRNA expression were significantly decreased by 58% and 7%, respectively. In contrast, pretreatment with DMA did not have any effect on the decreased Mrp2 expression and biliary excretion of GSH induced by LPS exposure. Taken together, our data clearly indicate that LPS-induced short-term rapid retrieval of Mrp2 from the canalicular surface resulted from LPS-induced oxidative stress, while the long-term transcriptional regulation of Mrp2 expression did not depend on the intracellular redox status.
Texto completo:
1
Base de dados:
MEDLINE
Medicinas Tradicionais:
Medicinas_tradicionales_de_asia
/
Medicina_china
Assunto principal:
Piperazinas
/
Regulação para Baixo
/
Lipopolissacarídeos
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Proteínas Associadas à Resistência a Múltiplos Medicamentos
Idioma:
En
Revista:
Biochem Pharmacol
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Japão