RESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Danshen, root of Salvia miltiorrhiza (SM), has been traditionally used in Chinese medicine for the treatment of heart, abdomen, gurgling in the intestines, and relieving fullness. However, the effects of SM on intestine have rarely been done to date. AIM OF THE STUDY: To investigate the contraction effect of SM on isolated rat ileum and its mechanisms involved. MATERIALS AND METHODS: The isometric contractions of ileum segments were investigated in organ baths for spontaneous activity and response to ethanolic extracts of SM. To determine the contraction mechanism caused by SM extracts, atropine (a muscarinic receptor antagonist), tetrodotoxin (TTX, a sodium channel blocker), nifedipine (a calcium channel blocker), Ca(2+) free Krebs solution with EGTA, or trifluoperazine (TFP, a calmodulin blocker) was administered and its response to cumulative dosages of SM extracts were examined. The effect of SM extracts on Ca(2+) signaling in the intestinal epithelial cell-6 (IEC-6) was examined using fura-2 as a Ca(2+) indicator. RESULTS: SM extracts caused dose-dependent tonic contraction on rat ileum in ex vivo organ bath studies. The contraction induced by SM extracts was not inhibited by atropine, TTX, nifedipine, or in Ca(2+) free solution. However, the ileal contractions induced by SM extracts were significantly inhibited by TFP in a dose-dependent manner. In IEC-6 cells, the SM extracts induced extracellular Ca(2+) entry and massive intracellular Ca(2+) release in Ca(2+)-contained medium, and induced intracellular Ca(2+) release in Ca(2+)-free medium. CONCLUSION: These results demonstrate that SM extracts cause ileal contraction through the Ca(2+)-calmodulin pathway.
Asunto(s)
Calcio/fisiología , Calmodulina/fisiología , Íleon/efectos de los fármacos , Extractos Vegetales/farmacología , Salvia miltiorrhiza , Abietanos/análisis , Animales , Atropina/farmacología , Bloqueadores de los Canales de Calcio/farmacología , Calmodulina/antagonistas & inhibidores , Línea Celular , Íleon/fisiología , Técnicas In Vitro , Masculino , Antagonistas Muscarínicos , Contracción Muscular/efectos de los fármacos , Nifedipino/farmacología , Extractos Vegetales/química , Raíces de Plantas/química , Ratas , Ratas Sprague-Dawley , Bloqueadores de los Canales de Sodio/farmacología , Tetrodotoxina/farmacología , Trifluoperazina/farmacologíaRESUMEN
INTRODUCTION: Biliary tract infection is associated with high mortality. This study investigated the effect of glucocorticoid pretreatment on lipopolysaccharide (LPS)-induced cholangitis. METHODS: Rats undergoing either sham operation or ligation of the extrahepatic bile duct (BDL) for 2 weeks were randomly assigned to receive intravenous injections of dexamethasone (DX) or normal saline (NS) prior to infusing LPS into the biliary tract. The plasma levels of tumor necrosis factor-alpha (TNFalpha), chemokines monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) as well as liver mRNA expression of MCP-1 and MIP-2 were determined. Infiltration of monocytes, Kupffer cells, and neutrophils in rat liver were studied with immunohistochemistry. Oxidative liver injury was measured by the malondialdehyde (MDA) content. RESULTS: Dexamethasone pretreatment resulted in significantly decreased plasma levels of TNFalpha at 1 hour, MCP-1 and MIP-2 at 2 and 3 hours, and decreased liver MCP-1 mRNA expression at 3 hours following LPS infusion in BDL-DX rats than in BDL-NS rats. The number of inflammatory cells in the liver was significantly different between sham- and BDL-treated rats but was not affected by DX pretreatment. Pretreatment with DX resulted in significantly decreased liver MDA contents in the BDL-DX group than that in the BDL-NS group. Jaundiced rats pretreated with 5 mg DX prior to infusion of 1 g of LPS were 6.8 times more likely to survive than those that were not pretreated. CONCLUSIONS: Pretreatment of jaundiced, LPS-treated rats with a supraphysiological dose of dexamethasone may rescue their lives by suppression of chemokine expression and alleviation of oxidative liver injury.
Asunto(s)
Colangitis/metabolismo , Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Ictericia/mortalidad , Hígado/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Animales , Quimiocina CCL2/biosíntesis , Quimiocina CXCL2 , Colangitis/complicaciones , Colangitis/patología , Ictericia/etiología , Lipopolisacáridos/administración & dosificación , Hígado/metabolismo , Masculino , Monocinas/biosíntesis , Ratas , Ratas Sprague-Dawley , Tasa de SupervivenciaRESUMEN
AIM: Biliary intervention may augment chemokine expression and inflammatory cell infiltration and aggravates liver injury in cholestatic rats. We tested the efficacy of glucocorticoid pretreatment to prevent the complications. METHODS: A model of biliary intervention was established in rats without (sham) or with bile duct ligation (BDL). Before biliary intervention, rats were randomly assigned to receiving intravenous injection of dexamethasone (DX group) or normal saline (NS group). Plasma levels of monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) were measured with enzyme-linked immunosorbent assay, and liver messenger RNA of these chemokines was quantified with real-time quantitative reverse transcriptase-polymerase chain reaction. Monocytes, Kupffer cells, and neutrophils in the rat liver were characterized with antibodies to ectodermal dysplasia 1 (ED1), ED2, and myeloperoxidase, respectively. RESULTS: By 3 hours after biliary intervention, plasma MCP-1 and MIP-2 proteins in BDL-NS rats were significantly higher than in BDL-DX. At 3 hours, liver MCP-1 and MIP-2 messenger RNA levels were significantly upregulated in BDL-NS than in BDL-DX. The amount of ED1-, ED2- and myeloperoxidase-staining cells were significantly greater in BDL-NS than in BDL-DX. Most of the changes returned to baseline levels by 24 hours. CONCLUSION: Glucocorticoid pretreatment suppresses chemokine expression and inflammatory cell infiltration, which may consequently alleviate liver injury in cholestatic rats receiving biliary intervention.
Asunto(s)
Quimiocinas/antagonistas & inhibidores , Colestasis/patología , Colestasis/terapia , Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Inflamación/patología , Premedicación , Animales , Quimiocina CCL2/sangre , Quimiocina CCL2/genética , Quimiocina CXCL2 , Quimiocinas CXC/sangre , Quimiocinas CXC/genética , Colestasis/metabolismo , Dexametasona/administración & dosificación , Ectodisplasinas , Glucocorticoides/administración & dosificación , Inyecciones Intravenosas , Hígado/metabolismo , Hígado/patología , Masculino , Proteínas de la Membrana/metabolismo , Peroxidasa/metabolismo , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Factores de Necrosis Tumoral/metabolismoRESUMEN
BACKGROUND: Intervention of the biliary system is frequently done in patients with obstructive jaundice and is associated with significant morbidity and mortality. The pathogenesis is unknown. MATERIALS AND METHODS: A rat model of bile duct ligation (BDL) for 2 weeks was established in which biliary intervention was feasible by injection of normal saline through an indwelling catheter in the bile ducts. Plasma levels of C-C chemokine MCP-1 and C-X-C chemokine MIP-2 were measured by using ELISA. Blood monocytes, Kupffer cells, and neutrophils in the liver were characterized with antibodies to ED1, ED2, and myeloperoxidase (MPO). Lipid peroxidation was measured by malondialdehyde contents and apoptosis by TUNEL stain of the liver. RESULTS: Biliary intervention resulted in an increase of plasma MCP-1 and MIP-2 proteins by 1 h, which declined to normal level by 3 h in both sham and BDL rats. The levels in BDL rats were significantly higher than in sham at most points. There was a transient increase of ED1- and ED2-positive cells and MPO-staining cells in sham rat liver by 1 h after intervention. ED2-positive cells increased significantly by 1 h, while ED1- and MPO-positive cells decreased, yet insignificantly after intervention in BDL rats. The cell counts in BDL were constantly higher than in sham. Malondialdehyde increased precipitously in BDL by 3 h and was significantly higher than in sham throughout the study period. Parenchymal liver injury, manifested by elevated ALT, as well as apoptosis and necrosis of liver cells, was significantly increased in BDL rats, but not in sham rats. CONCLUSION: Biliary intervention augments chemokine expression, precipitates lipid peroxidation, and aggravates liver injury in cholestatic rats.