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1.
J Viral Hepat ; 16(8): 586-94, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19552664

RESUMEN

The impact of ribavirin exposure on virologic relapse remains controversial in combination therapy with pegylated interferon (Peg-IFN) and ribavirin for patients with chronic hepatitis C (CH-C) genotype 1. The present study was conducted to investigate this. Nine hundred and eighty-four patients with CH-C genotype 1 were enrolled. The drug exposure of each medication was calculated by averaging the dose actually taken. For the 472 patients who were HCV RNA negative at week 24 and week 48, multivariate logistic regression analysis showed that the degree of fibrosis (P = 0.002), the timing of HCV RNA negativiation (P < 0.001) and the mean doses of ribavirin (P < 0.001) were significantly associated with relapse, but those of Peg-IFN were not. Stepwise reduction of the ribavirin dose was associated with a stepwise increase in relapse rate from 11% to 60%. For patients with complete early virologic response (c-EVR) defined as HCV RNA negativity at week 12, only 4% relapse was found in patients given > or = 12 mg/kg/day of ribavirin and ribavirin exposure affected the relapse even after treatment week 12, while Peg-IFN could be reduced to 0.6 microg/kg/week after week 12 without the increase of relapse rate. Ribavirin showed dose-dependent correlation with the relapse. Maintaining as high a ribavirin dose as possible (> or = 12 mg/kg/day) during the full treatment period can lead to suppression of the relapse in HCV genotype 1 patients responding to Peg-IFN alpha-2b plus ribavirin, especially in c-EVR patients.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Anciano , Relación Dosis-Respuesta a Droga , Femenino , Genotipo , Hepacivirus/genética , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , ARN Viral/sangre , Proteínas Recombinantes , Recurrencia , Ribavirina/administración & dosificación , Resultado del Tratamiento
2.
J Viral Hepat ; 16(8): 578-85, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19552663

RESUMEN

Chronic hepatitis C (CH-C) genotype 1 patients who achieved early virologic response have a high probability of sustained virologic response (SVR) following pegylated interferon (Peg-IFN) plus ribavirin therapy. This study was conducted to evaluate how reducing drug doses affects complete early virologic response (c-EVR) defined as hepatitis C virus (HCV) RNA negativity at week 12. Nine hundred eighty-four patients with CH-C genotype 1 were enrolled. Drug doses were evaluated independently on a body weight base from doses actually taken. From multivariate analysis, the mean dose of Peg-IFN alpha-2b during the first 12 weeks was the independent factor for c-EVR (P = 0.02), not ribavirin. The c-EVR rate was 55% in patients receiving > or = 1.2 microg/kg/week of Peg-IFN, and declined to 38% at 0.9-1.2 microg/kg/week, and 22% in patients given <0.9 microg/kg/week (P < 0.0001). Even with stratified analysis according to ribavirin dose, the dose-dependent effect of Peg-IFN on c-EVR was observed, and similar c-EVR rates were obtained if the dose categories of Peg-IFN were the same. Furthermore, the mean dose of Peg-IFN during the first 12 weeks affected HCV RNA negativity at week 24 (P < 0.0001) and SVR (P < 0.0001) in a dose-dependent manner. Our results suggest that Peg-IFN was dose-dependently correlated with c-EVR, independently of ribavirin dose. Thus, maintaining the Peg-IFN dose as high as possible during the first 12 weeks can yield HCV RNA negativity and higher c-EVR rates, leading to better SVR rates in patients with CH-C genotype 1.


Asunto(s)
Antivirales/uso terapéutico , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/virología , Interferón-alfa/uso terapéutico , Polietilenglicoles/uso terapéutico , Ribavirina/uso terapéutico , Anciano , Relación Dosis-Respuesta a Droga , Femenino , Genotipo , Hepacivirus/genética , Humanos , Interferón alfa-2 , Interferón-alfa/administración & dosificación , Masculino , Persona de Mediana Edad , Polietilenglicoles/administración & dosificación , ARN Viral/sangre , Proteínas Recombinantes , Resultado del Tratamiento
3.
J Viral Hepat ; 8(3): 180-5, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11380795

RESUMEN

The aim of this study was to clarify the immunological and virological responses to pre-administration of interferon-gamma prior to initiation of interferon-alpha treatment in patients with refractory chronic hepatitis C. Twenty-two nonresponders to 6-months of IFN-alpha treatment were enrolled. The hepatitis C virus (HCV) genotype was Ib in all. Natural IFN-gamma (1 MIU/day) was administered daily for 14 days followed by natural IFN-alpha (5 MIU/day) daily for 14 days and then three times weekly for 22 weeks. Serum immunological parameters (IL-10, neopterin, BMG, sCD8, sCD4, IL-6, IL-12) were measured as were the levels of several cytokines (IFN-gamma, TNF-alpha, IL-2, IL-4, IL-5, IL-6, IL-10). Three patients dropped out; two because of the occurrence of other diseases and one because of an adverse effect. At the end of the period of IFN-alpha treatment, HCV-RNA had become negative in six of 19 patients (end-of treatment response; ETR). Six months after the completion of IFN administration, a virological sustained response (SR) was seen in two of 19 patients. The mean serum levels of IL-10 were significantly decreased 6 weeks after the start of treatment. Other immunological parameter levels increased significantly during the period of IFN-gamma administration, and tended to return to the pretreatment level after the start of IFN-alpha administration. Univariate logistic regression analysis showed that the initial change in the levels of these parameters or the change in the ratios of Th1/Th2 parameter levels are useful factors indicative of the end of the treatment response. These findings suggest that priming with IFN-gamma prior to the initiation of IFN-alpha treatment in patients with refractory chronic hepatitis C can modulate the host immune response and this might contribute to viral clearance.


Asunto(s)
Antivirales/administración & dosificación , Hepacivirus/inmunología , Hepatitis C Crónica/tratamiento farmacológico , Hepatitis C Crónica/inmunología , Interferón-alfa/administración & dosificación , Interferón gamma/administración & dosificación , Antivirales/efectos adversos , Antígenos CD4/sangre , Antígenos CD8/sangre , Citocinas/sangre , Esquema de Medicación , Femenino , Hepacivirus/genética , Hepatitis C Crónica/virología , Humanos , Interferón-alfa/efectos adversos , Interferón gamma/efectos adversos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Neopterin/sangre , ARN Viral/química , ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Carga Viral , Microglobulina beta-2/sangre
4.
Cancer Gene Ther ; 7(10): 1341-7, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11059692

RESUMEN

Mammalian degenerin (MDEG) is a member of the amiloride-sensitive sodium ion channel family, and its site-directed active mutant (MDEG-G430F) induces massive Na+ influx into cells, leading to cell ballooning and cell bursting. We attempted a novel therapeutic approach for gastric cancers by transferring MDEG-G430F into cancer cells using tumor-specific promoters. In carcinoembryonic antigen (CEA)-producing gastric cancer cells, the level of cell death observed when MDEG-G430F was used with a CEA promoter was similar to that observed when using a potent nonspecific promoter such as the cytomegalovirus promoter. In an in vivo study, fusogenic liposome complexes containing MDEG-G430F driven by the CEA promoter were injected intraperitoneally into CEA-producing gastric cancer cells in a mouse peritoneal dissemination model. Although all 15 of the control mice were dead by 50 days postinoculation, 13 of the 15 mice treated with MDEG-G430F survived. These results indicate that transferring MDEG-G430F into cancer tissues using tumor-specific promoters can achieve striking and selective cancer cell death irrespective of the transcriptional efficiency of the promoters used in vivo, and suggest that this approach is a promising new strategy for cancer gene therapy.


Asunto(s)
Antígeno Carcinoembrionario/genética , Canales Iónicos/genética , Canales Iónicos/uso terapéutico , Neoplasias Hepáticas/terapia , Mutagénesis Sitio-Dirigida/genética , Mutación/genética , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/uso terapéutico , Neoplasias Gástricas/terapia , Transducción Genética/métodos , Canales Iónicos Sensibles al Ácido , Animales , Antígeno Carcinoembrionario/biosíntesis , Supervivencia Celular/efectos de los fármacos , Canales de Sodio Degenerina , Canales Epiteliales de Sodio , Femenino , Humanos , Inyecciones Intraperitoneales , Canales Iónicos/metabolismo , Liposomas , Neoplasias Hepáticas/metabolismo , Luciferasas/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Trasplante de Neoplasias , Proteínas del Tejido Nervioso/metabolismo , Enfermedades Peritoneales/patología , Tasa de Supervivencia , Factores de Tiempo , Células Tumorales Cultivadas
6.
J Med Virol ; 55(2): 98-102, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9598928

RESUMEN

A novel virus (GBV-C/HGV) may be associated with some liver diseases including fulminant hepatitis and acute and chronic hepatitis. On the other hand, many investigations showed that this infection does not contribute to liver disease. GBV-C/HGV has been found to occur in association with infection with other hepatitis viruses. We investigated the effect of GBV-C/HGV infection on the clinical features and interferon treatment in patients with chronic hepatitis C. A total of 262 hepatitis C virus (HCV) RNA positive patients with chronic hepatitis were examined in this study. The detection of serum GBV-C/HGV RNA was done by RT-PCR using specific primers from the NS5 regions. Interferon-alpha was given at a dose of 6 MU/day for 16 or 24 weeks. A responder was defined as a patient with ALT normalization and HCV RNA disappearance after treatment. GBV-C/HGV RNA was detected in 28 (11%) patients. No significant difference was detected in clinical features (age, sex, liver-related biochemical tests, and histological examination) between the 28 GBV-C/HGV-positive patients and the GBV-C/HGV-negative patients. Using interferon therapy for hepatitis C, the responder rates of GBV-C/HGV-positive and -negative patients were 14% and 20%, respectively. Of the 28 patients with GBV-C/HGV RNA, GBV-C/HGV RNA was tested after interferon therapy in 16 and of these GBV-C/HGV RNA was not detected in nine patients after therapy. These findings suggest that GBV-C/HGV infection dose not affect the clinical features in patients with HCV and the efficacy of interferon therapy for chronic hepatitis C.


Asunto(s)
Flaviviridae/fisiología , Hepatitis C Crónica/fisiopatología , Hepatitis C Crónica/terapia , Hepatitis Viral Humana/terapia , Interferón-alfa/uso terapéutico , Adolescente , Adulto , Anciano , Femenino , Flaviviridae/genética , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/virología , Hepatitis Viral Humana/complicaciones , Hepatitis Viral Humana/fisiopatología , Hepatitis Viral Humana/virología , Humanos , Masculino , Persona de Mediana Edad , ARN Viral
7.
J Hepatol ; 26(3): 574-83, 1997 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9075665

RESUMEN

BACKGROUND/AIMS/METHODS: The imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) is considered to be an important determinant of extracellular matrix deposition and breakdown. We measured serum MMP-1, MMP-2, TIMP-1 and TIMP-2 levels using the respective one-step sandwich enzyme immunoassays in 98 patients with chronic hepatitis C treated with interferon beta to examine their clinical significance for assessment of liver histology and to determine whether they can be useful as predictors of the interferon response. RESULTS: Serum TIMP-1 levels showed a positive correlation with the degree of fibrosis (r(s)=0.30, p= 0.004). Serum MMP-2 levels revealed positive relationships with the degree of periportal necrosis (r(s)= 0.32, p=0.002), the degree of fibrosis (r(s)=0.26, p= 0.01) and total score of histological activity index (r(s)=0.24, p=0.02). Serum MMP-2 levels were significantly higher in patients with no response than in those with sustained and transient response (p<0.01 and p<0.05, respectively), while serum MMP-1 levels did not differ among the three groups. Compared with the levels in sustained responders, the total amounts of serum TIMP-1 were significantly lower in transient responders and non-responders (p<0.01 and p<0.001, respectively). As for serum TIMP-2 levels, a significant decrease was found in transient responders and non-responders (p<0.01). The ratios of serum MMP-2 to TIMP-1 levels were significantly higher in transient responders and non-responders than in sustained responders (p<0.001, respectively) even when HCV RNA levels were low in patients with HCV genome subtype 1b or when the HCV genome subtype was 2a or 2b. Sustained response was never found in type 1b patients with ratios of serum MMP-2 to TIMP-1 levels of over 6.0. In logistic multivariate regression analysis, the ratios of serum MMP-2 to TIMP-1 level (p=0.0001), HCV genome subtype (p=0.005) and serum TIMP-2 level (p=0.03) were the independent predictors for sustained response, while serum MMP-2 level (p=0.0006) was the only predictor for no response. CONCLUSIONS: Serum MMP-2 and TIMP-1 levels might be useful for estimating the degree of liver fibrosis. The ratio of serum MMP-2 to TIMP-1 levels may serve as a new predictor of interferon response in patients with chronic hepatitis C.


Asunto(s)
Gelatinasas/sangre , Glicoproteínas/sangre , Hepatitis C/enzimología , Cirrosis Hepática/enzimología , Metaloendopeptidasas/sangre , Inhibidores de Proteasas/sangre , Alanina Transaminasa/sangre , Anticuerpos Antivirales/inmunología , Antivirales/administración & dosificación , Antivirales/uso terapéutico , Biomarcadores/sangre , Enfermedad Crónica , Colagenasas/sangre , Femenino , Estudios de Seguimiento , Genoma Viral , Hepacivirus/genética , Hepacivirus/inmunología , Hepatitis C/patología , Hepatitis C/terapia , Humanos , Técnicas para Inmunoenzimas , Inyecciones Intravenosas , Interferón beta/administración & dosificación , Interferón beta/uso terapéutico , Cirrosis Hepática/patología , Masculino , Metaloproteinasa 1 de la Matriz , Metaloproteinasa 2 de la Matriz , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Proteínas/metabolismo , ARN Viral/análisis , Inhibidor Tisular de Metaloproteinasa-2 , Inhibidores Tisulares de Metaloproteinasas , Resultado del Tratamiento
8.
Ann Nucl Med ; 11(1): 27-32, 1997 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9095319

RESUMEN

We recently reported that transrectal or intestinal portal scintigraphy with 123I-iodoamphetamine (IMP) could be a useful method for the non-invasive and quantitative evaluation of the portosystemic shunt in portal hypertension, but what cells in the liver trap IMP has not been clarified. This study was aimed at elucidating whether IMP was extracted by parenchymal cells, sinusoidal endothelial cells, Kupffer cells or fat storing cells. Each type of liver cell was isolated from rats and cultured. The cells were incubated with 125I-IMP and the radioactivity of the lysate was determined. Nonspecific binding was assessed in the presence of an excess of unlabeled IMP, and specific binding was determined by subtracting the nonspecific from total binding. Specific binding observed in parenchymal cells, endothelial cells and Kupffer cells was 70.2 +/- 0.4, 4.2 +/- 1.4 and 2.3 +/- 0.8 pmol/well, respectively, but no specific binding was observed in fat storing cells. The binding in parenchymal cells was much higher than that in endothelial cells or Kupffer cells (p < 0.005). In addition, the binding to parenchymal cells reached equilibrium within 20 min and was not saturable over the concentration range tested (0.5-10 microM). These findings indicate that IMP is mostly extracted by parenchymal cells in the liver.


Asunto(s)
Anfetaminas/metabolismo , Hígado/citología , Hígado/metabolismo , Animales , Células Cultivadas , Endotelio/citología , Endotelio/diagnóstico por imagen , Endotelio/metabolismo , Humanos , Radioisótopos de Yodo , Cinética , Macrófagos del Hígado/diagnóstico por imagen , Macrófagos del Hígado/metabolismo , Hígado/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Pulmón/metabolismo , Derivación Portosistémica Quirúrgica , Cintigrafía , Ratas
9.
Biochem Biophys Res Commun ; 204(2): 468-74, 1994 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-7980502

RESUMEN

To investigate the role that Fas ligand plays in the apoptosis of hepatocytes induced by hepatitis C virus infection, we isolated a cDNA clone for human Fas ligand and examined the expression of Fas ligand in liver-infiltrating mononuclear cells obtained from patients with chronic hepatitis C. The amino acid sequence of human Fas ligand showed 76% and 77% identity with those of rat and mouse Fas ligand, respectively. When the expression of Fas ligand transcripts was tested by reverse transcription-polymerase chain reaction, the amplified signal was detected in liver-infiltrating mononuclear cells and peripheral blood mononuclear cells, whereas only a weak signal or none at all was detected in liver tissues. These findings suggest that the Fas ligand-Fas antigen system may play an important role in liver cell injury by hepatitis C virus infection.


Asunto(s)
Apoptosis , Hepatitis C/patología , Glicoproteínas de Membrana/fisiología , Secuencia de Aminoácidos , Animales , Secuencia de Bases , ADN Complementario , Proteína Ligando Fas , Humanos , Hígado/patología , Ratones , Datos de Secuencia Molecular , ARN Mensajero/genética , Ratas
10.
Hepatology ; 20(4 Pt 1): 961-5, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7927238

RESUMEN

The purpose of this study was to clarify the role of endogenous nitric oxide in ethanol-induced perturbation of microcirculation and hepatic injury in perfused rat liver. Infusion of ethanol into the portal vein at 25 and 100 mmol/L increased portal pressure, which is an indicator of hepatic vasoconstriction, in a concentration-dependent fashion. Portal pressure started to rise immediately after ethanol load, then decreased gradually and remained at higher than basal levels throughout the period of ethanol infusion. Release of lactate dehydrogenase into the effluent perfusate began to increase after 30 min of ethanol infusion and continued to increase during the 60-min period of ethanol infusion. The lactate dehydrogenase level in the effluent perfusate at 60 min was dependent on the ethanol concentration (0 mmol/L, 8 +/- 3 IU/L; 25 mmol/L, 16 +/- 2 IU/L; 100 mmol/L, 52 +/- 6 IU/L). Simultaneous infusion of NG-monomethyl-L-arginine, a nitric oxide synthesis inhibitor, enhanced significantly the ethanol-induced increase in portal pressure by 100% to 400% and increased lactate dehydrogenase release by 40% to 80%. The effect of NG-monomethyl-L-arginine on the ethanol-induced increase in portal pressure was completely reversed by the co-infusion of an excess dose of L-arginine. Change in portal pressure averaged over 60 min of ethanol infusion correlated with levels of lactate dehydrogenase release 60 min after the initiation of ethanol infusion (r = 0.77, p < 0.01). In conclusion, inhibition of the action of endogenous nitric oxide was associated with an increase in hepatic vasoconstriction and hepatocellular damage.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Etanol/efectos adversos , Circulación Hepática/efectos de los fármacos , Hígado/efectos de los fármacos , Óxido Nítrico/fisiología , Análisis de Varianza , Animales , Arginina/análogos & derivados , Arginina/farmacología , Técnicas In Vitro , L-Lactato Deshidrogenasa/metabolismo , Hígado/enzimología , Hígado/patología , Masculino , Microcirculación/efectos de los fármacos , Óxido Nítrico/biosíntesis , Perfusión , Presión Portal/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Vasoconstricción/efectos de los fármacos , omega-N-Metilarginina
11.
Drug Metab Dispos ; 22(5): 680-7, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7835217

RESUMEN

This study investigates the possible role of Kupffer cells in storage and metabolism of benzo(a)pyrene in the liver. In perfused liver, benzo(a)pyrene (4-120 microM) in 0.3% albumin increased fluorescence (366-->405 mm) on the liver surface in a dose-dependent manner, suggesting that it accumulated in liver tissue. The maximal increase of benzo(a)pyrene fluorescence was diminished by 60% when Kupffer cells were destroyed by gadolinium chloride treatment (10 mg/kg iv). Gadolinium chloride also decreased the yield of isolated nonparenchymal cells by 65%. In frozen sections of livers perfused with 4 microM benzo(a)pyrene for 1 hr, fluorescence was approximately 5 times greater in cells lining the sinusoids than in parenchymal cells. Moreover, yellow-green fluorescent particles were detected in cultured Kupffer cells, but were barely visible in parenchymal and Ito cells, indicating that Kupffer cells actively accumulated benzo(a)pyrene. In contrast to the cell specificity for benzo(a)pyrene accumulation, rates of monooxygenation of benzo(a)pyrene were up to 20-fold higher in isolated parenchymal than in Kupffer cells. In nonparenchymal cells, basal rates of production of benzo(a)pyrene phenols were approximately 50 pmol/10(6) cells/hr. In contrast, rates were approximately 335 pmol/10(6) cells/hr in parenchymal cells. Further, total [3H]benzo(a)pyrene metabolism was approximately 8-fold higher in parenchymal than in nonparenchymal cells. Albumin increased production of benzo(a)pyrene phenols by 3-fold in parenchymal cells, but was without effect in nonparenchymal cells. Pretreatment of rats with gadolinium chloride increased the production of benzo(a)pyrene phenols in perfused liver by > 50%.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Benzo(a)pireno/metabolismo , Macrófagos del Hígado/metabolismo , Hígado/citología , Hígado/metabolismo , Animales , Bilis/metabolismo , Células Cultivadas , Femenino , Gadolinio/farmacología , Glucuronatos/metabolismo , Técnicas In Vitro , Macrófagos del Hígado/efectos de los fármacos , Hígado/efectos de los fármacos , Perfusión , Fenoles/metabolismo , Ratas , Ratas Sprague-Dawley
12.
Alcohol Alcohol Suppl ; 29(1): 5-7, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-9063819

RESUMEN

This study investigated the role of endogenous nitric oxide in the regulation of hepatic vascular tone in the presence of ethanol. In the perfused rat liver, upon the initiation of ethanol infusion into the liver, portal pressure was increased in a dose-dependent manner, reaching maximal levels in 2-5 min, then decreasing gradually. Simultaneous infusion of N(G)-monomethy 1-L-arginine, a nitric oxide synthesis inhibitor, enhanced this ethanol-induced increase in portal pressure. This enhancement was reversed by simultaneous infusion of a precursor of nitric oxide, L-arginine. These results suggest that endogenous nitric oxide acts as a vasodilator which reduces ethanol-induced vasoconstriction, thus improving the perturbation of hepatic microcirculation by ethanol.


Asunto(s)
Etanol/sangre , Hígado/química , Óxido Nítrico/fisiología , Animales , Humanos , Masculino , Ratas , Ratas Sprague-Dawley
13.
Alcohol Alcohol Suppl ; 2: 353-6, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8974355

RESUMEN

Microcirculatory disturbance is one of the main pathogenetic features of alcoholic liver damage. We have demonstrated that ethanol increased portal pressure, leading to hepatic hypoxia and hepatocellular necrosis. In this ethanol-induced hepatic vasoconstriction, nitric oxide, an endothelial derived relaxing factor, dilated constrictive hepatic vasculature and reduced liver injury by improving the microcirculatory disturbance.


Asunto(s)
Etanol/toxicidad , Circulación Hepática/efectos de los fármacos , Circulación Hepática/fisiología , Óxido Nítrico/fisiología , Animales , Inhibidores Enzimáticos/farmacología , Técnicas In Vitro , Hígado/irrigación sanguínea , Hígado/efectos de los fármacos , Hígado/lesiones , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/fisiopatología , Masculino , Microcirculación/efectos de los fármacos , Microcirculación/fisiología , Modelos Biológicos , Óxido Nítrico Sintasa/antagonistas & inhibidores , Perfusión , Ratas , Ratas Sprague-Dawley , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiología , omega-N-Metilarginina/farmacología
14.
Hepatology ; 18(2): 400-5, 1993 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-7687982

RESUMEN

Kupffer cells, the resident hepatic macrophages, are activated by calcium, and several reports indicate that their function (e.g., phagocytosis and cytokine production) is altered by ethanol. We recently found that Kupffer cells contain L-type voltage-dependent Ca2+ channels. The purpose of this study, therefore, was to evaluate the effect of short-term ethanol treatment on voltage-dependent Ca2+ channels in Kupffer cells. Kupffer cells were isolated from rats 2 hr after intragastric administration of ethanol (5 gm/kg intragastrically). Cytosolic free calcium concentration of cultured Kupffer cells was measured with the fluorescent Ca2+ indicator fura-2. In Kupffer cells isolated from control rats, partial replacement of extracellular Na+ by K+ caused an increase in cytosolic free calcium concentration in a concentration-dependent manner (half-maximal effect was observed with 81 mmol/L K+), presumably because of membrane depolarization. Acute ethanol treatment in vivo shifted the concentration-response curve for K+ to the right (half-maximal effect was observed with 94 mmol/L K+) and reduced the maximal elevation of cytosolic free calcium concentration by means of K+. Significantly, the dihydropyridine-type calcium channel agonist BAY K 8644 (1 mumol/L) shifted the concentration-response curve for K+ to the left in control and ethanol-treated groups (half-maximal effect was observed with 61 and 77 mmol/L K+, respectively). Moreover, the dihydropyridine-type calcium channel blocker nitrendipine (10 mumol/L) prevented the increase in cytosolic free calcium concentration in both groups. When extracellular Ca2+ was omitted from the incubation medium, the increases in cytosolic free calcium concentration due to depolarization were prevented completely. However, direct addition of ethanol to the cell cultures was without effect.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Canales de Calcio/efectos de los fármacos , Canales de Calcio/fisiología , Etanol/farmacología , Macrófagos del Hígado/metabolismo , Ácido 3-piridinacarboxílico, 1,4-dihidro-2,6-dimetil-5-nitro-4-(2-(trifluorometil)fenil)-, Éster Metílico/farmacología , Animales , Calcio/metabolismo , Células Cultivadas , Electrofisiología , Etanol/sangre , Espacio Extracelular/metabolismo , Femenino , Membranas Intracelulares/metabolismo , Nitrendipino/farmacología , Concentración Osmolar , Potasio/metabolismo , Potasio/farmacología , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
15.
J Nucl Med ; 34(7): 1103-8, 1993 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8315486

RESUMEN

Portal circulation changes due to the progression of chronic liver disease and portal venous flow are also affected by pharmacotherapy. Thus, noninvasive measurement of effective portal venous flow (EPVF) is highly desirable. We evaluated EPVF under steady-state conditions using echo-Doppler flowmetry combined with per jejunal portal scintigraphy in 32 patients with chronic liver disease. After introduodenal administration of 37 MBq (1 mCi) of 123I-iodoamphetamine, scintigraphy of the pulmonary and hepatic regions was performed and a portosystemic shunt index (SI) calculated. EPVF was calculated as follows: EPVF = PVFx (1-SI/100). EPVF in chronic hepatitis, compensated cirrhosis and decompensated cirrhosis was 12.0 +/- 1.8 ml/min/kg, 10.3 +/- 1.6 ml/min/kg and 8.0 +/- 2.5 ml/min/kg, respectively. There were significant differences in EPVF between all groups, although PVF was similar in each group. EPVF correlated with liver function tests and was a better indicator of liver function than PVF. Measurement of EPVF may provide useful information in the management of patients with chronic liver disease.


Asunto(s)
Hepatitis/fisiopatología , Cirrosis Hepática/fisiopatología , Hígado/diagnóstico por imagen , Pulmón/diagnóstico por imagen , Sistema Porta/fisiología , Adulto , Anfetaminas , Enfermedad Crónica , Femenino , Hepatitis/diagnóstico por imagen , Humanos , Radioisótopos de Yodo , Yofetamina , Circulación Hepática/fisiología , Cirrosis Hepática/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Sistema Porta/diagnóstico por imagen , Cintigrafía , Reología , Ultrasonido
16.
J Clin Invest ; 91(4): 1337-42, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8473486

RESUMEN

This study was designed to investigate the mechanism for ethanol-induced hepatic vasoconstriction in isolated perfused rat liver. Upon initiation of ethanol infusion into the portal vein at concentrations ranging from 25 to 100 mM, portal pressure began to increase in a concentration-dependent manner and reached maximal levels in 2-5 min (initial phase), followed by a gradual decrease over the period of ethanol infusion (escape phenomenon). Endothelin-1 antiserum significantly inhibited this ethanol-induced hepatic vasoconstriction by 45-80%. Cessation of infusion of endothelin-1 antiserum was followed by a subsequent increase in portal pressure. On the other hand, when a nitric oxide synthesis inhibitor, NG-monomethyl-L-arginine (L-NMMA), was infused into the portal vein simultaneously with ethanol, the initial phase of the response of portal pressure to ethanol was not altered and the peak values of portal pressure remained unchanged. However, after the peak increase in portal pressure, the rate of decrease was less than in the absence of L-NMMA. Thus, L-NMMA diminished the escape phenomenon and sustained the vasoconstriction. This study supports the hypothesis that two endothelium-derived vasoactive factors, endothelin-1 and nitric oxide, regulate hepatic vascular tone in the presence of ethanol.


Asunto(s)
Endotelinas/fisiología , Etanol/farmacología , Hígado/irrigación sanguínea , Óxido Nítrico/metabolismo , Vasoconstricción/efectos de los fármacos , Animales , Arginina/análogos & derivados , Arginina/farmacología , Presión Sanguínea/efectos de los fármacos , Endotelinas/inmunología , Sueros Inmunes/farmacología , Masculino , Ratas , Ratas Sprague-Dawley , omega-N-Metilarginina
18.
Hepatology ; 16(4): 1007-13, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1398480

RESUMEN

The role of microcirculation in the pathogenesis of alcoholic liver injury was investigated in isolated perfused livers from fed rats. Infusion of ethanol into the portal vein at concentrations ranging from 25 to 200 mmol/L increased portal pressure, which is an indicator of hepatic vasoconstriction, in a concentration-dependent fashion. Portal pressure started to rise immediately on initiation of ethanol load and remained at higher than basal levels throughout the period of ethanol infusion. Release of lactate dehydrogenase, an indicator of cell injury, into the effluent perfusate began to increase after 20 to 30 min of ethanol infusion and continued to increase until the end of the experiment (60 min after the initiation of ethanol infusion). The lactate dehydrogenase level in the effluent perfusate at 60 min was dependent on the ethanol concentration (0 mmol/L, 8 +/- 3 IU/L; 25 mmol/L, 22 +/- 3 IU/L; 50 mmol/L, 51 +/- 11 IU/L; 100 mmol/L, 60 +/- 7 IU/L; 200 mmol/L, 120 +/- 7 IU/L). Simultaneous infusion of sodium nitroprusside (100 mumol/L), a known vasodilator, inhibited significantly the ethanol-induced increases in portal pressure and lactate dehydrogenase release by abolishing hepatic vasoconstriction. In histological examinations focal hepatocellular necrosis, evidenced by trypan blue staining of cell nuclei, was detected predominantly in midzonal and pericentral areas of the liver lobule after 60 min of ethanol infusion. Change in portal pressure during 60 min of ethanol infusion correlated significantly with levels of lactate dehydrogenase after ethanol infusion (r = 0.82; p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Etanol/farmacología , Circulación Hepática/efectos de los fármacos , Hígado/efectos de los fármacos , Vasoconstricción , Animales , Técnicas In Vitro , Hígado/patología , Masculino , Necrosis , Nitroprusiato/farmacología , Consumo de Oxígeno/efectos de los fármacos , Perfusión , Sistema Porta/efectos de los fármacos , Presión , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
19.
Am J Physiol ; 262(4 Pt 1): G645-50, 1992 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1348904

RESUMEN

The effect of several hormones known to alter intracellular free Ca2+ on rates of O2 uptake in periportal and pericentral regions of the liver lobule was studied in the perfused liver. Regional O2 uptake was measured by stopping the flow and monitoring the decrease in O2 concentration. When perfusion was in the anterograde direction, basal rates of O2 uptake were two to three times higher in periportal than in pericentral regions, and phosphorylase alpha activity, which increases as a function of intracellular free Ca2+ levels, was higher in periportal regions. In contrast, when perfusion was in the retrograde direction, rates of O2 uptake were two to three times greater in pericentral regions. Infusion of epinephrine (0.1 microM) or angiotensin II (5 nM) increased the rate of O2 uptake nearly exclusively in downstream areas of the lobule where O2 tension was low. When perfusions were in the anterograde direction, epinephrine increased phosphorylase alpha activity significantly only in pericentral regions. Stimulation of O2 uptake by epinephrine was blocked by the alpha-adrenergic receptor blocker phentolamine (1 microM) but not by the beta-receptor blocker propranolol. Thus hormones that increase intracellular calcium stimulate O2 uptake predominantly in regions of the liver lobule where O2 tension is lowest, supporting the hypothesis that oxygen tension regulates O2 uptake in the liver via mechanisms involving intracellular free Ca2+.


Asunto(s)
Hormonas/fisiología , Hígado/metabolismo , Consumo de Oxígeno , Antagonistas Adrenérgicos alfa/farmacología , Antagonistas Adrenérgicos beta/farmacología , Angiotensina II/farmacología , Animales , Calcimicina/farmacología , AMP Cíclico/metabolismo , Femenino , Consumo de Oxígeno/efectos de los fármacos , Fosforilasa a/metabolismo , Ratas , Ratas Endogámicas , Distribución Tisular
20.
Hepatology ; 15(3): 432-7, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1544623

RESUMEN

The purpose of this study was to determine whether hepatic tissue oxygenation after ischemia-reperfusion procedures is an indicator for later liver injury. Partial ischemia in the liver was induced by ligating the left pedicles. Rats were divided into two groups according to duration of ischemia: group A (30-min ischemia) and group B (60-min ischemia). Indices of blood oxygenation and blood volume in regional hepatic tissue, serum ALT levels and histological appearance of livers were evaluated. Twenty-four hours after ischemia and reflow, all rats in group A were alive, whereas only 67% survived in group B. Blood-oxygenation index and blood-volume index in group A rats rebounded quickly after reperfusion. In group B, blood-oxygenation index and blood-volume index remained significantly lower than in group A after reperfusion. Serum ALT levels at 60 and 120 min after reperfusion in group B were significantly higher than those in group A. Blood-oxygenation index measured at 5 and 60 min of reperfusion showed significant correlation with serum ALT levels at 120 min of reperfusion. When the percentage recovery of blood-oxygenation index at 5 and 60 min after reperfusion was more than 75%, all rats survived. No obvious signs of hepatocellular degeneration were observed histologically 5 min after reperfusion; however, substantial hepatocellular degeneration had occurred at 120 min of reperfusion in groups A and B. These data indicate that a decline in hepatic tissue oxygenation during the early phase of reperfusion (even when no obvious hepatocellular degeneration has been observed) can be a predictor of subsequent liver injury and prognosis.


Asunto(s)
Circulación Hepática , Hígado/metabolismo , Consumo de Oxígeno , Daño por Reperfusión/metabolismo , Alanina Transaminasa/sangre , Animales , Hemoglobinas/metabolismo , Hígado/patología , Masculino , Pronóstico , Ratas , Ratas Endogámicas , Daño por Reperfusión/patología , Espectrofotometría
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