RESUMEN
Low pretreatment viral load has consistently been shown to be an independent predictor of sustained response (SR) in patients with chronic hepatitis C infection. We assessed the efficacy of interferon (IFN) plus ribavirin vs IFN alone in low viraemic patients (<2 millions copies/mL) who had relapsed to a previous course of IFN and the efficacy of 24 vs 48 week combination therapy in high viraemic patients. Two hundred and ninety-seven patients were randomly assigned to one of the four regimens after stratification on pretreatment viral load. All patients received IFN-alpha2b (6 million units thrice weekly for 24 weeks and 3 million units thrice weekly for 24 weeks). Patients with low viraemia received either IFN-alpha2b alone for 48 weeks (R1: 42 patients) or IFN-alpha2b plus ribavirin (600 mg/day) for 24 weeks and IFN-alpha2b alone for the next 24 weeks (R2: 48 patients). Patients with high viral load received either IFN-alpha2b plus ribavirin for 24 weeks and then IFN-alpha2b alone for the next 24 weeks (R3: 104 patients) or IFN-alpha2b plus ribavirin for 48 weeks (R4: 103 patients). In low viraemic patients the rate of SR was 37.7% in group R1 and 59.6% in group R2 (P < 0.05). In high viraemic patients, the rate of SR was 44.7% in group R3 and 51.4% in group R4 (P: NS). Thirty-one patients discontinued treatment (10.4%) without difference regarding treatment regimen. In the regimen using ribavirin we found no difference in terms of SR between patients receiving a dose of ribavirin below 10.6 mg/kg/day (55%) or over 10.6 mg/kg/day (58%). Histological improvement occurred in 70.2% of patients regardless of the regimen. Logistic regression showed that genotype 2 and 3, Knodell score <6 and alanine aminotransferase pretreatment level >3 x upper limit of normal were significantly and independently correlated with SR. In low viraemic patients who relapsed to a previous IFN treatment, combination therapy using high-dose IFN and low-dose ribavirin is better than high-dose IFN alone. In high viraemic patients there was no benefit in increasing the duration of combination therapy from 24 to 48 weeks. In this study, it was found that low dose of ribavirin can be used safely and there is no effect of ribavirin dose on SR.
Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Ribavirina/uso terapéutico , Viremia/tratamiento farmacológico , Adulto , Quimioterapia Combinada , Femenino , Hepacivirus/efectos de los fármacos , Hepacivirus/fisiología , Hepatitis C Crónica/virología , Humanos , Interferón alfa-2 , Masculino , Persona de Mediana Edad , Estudios Prospectivos , ARN Viral/sangre , Proteínas Recombinantes , Recurrencia , Retratamiento , Resultado del Tratamiento , Carga Viral , Viremia/virologíaRESUMEN
BACKGROUND/AIMS: Electroneutral absorption of NaCl by the gallbladder mucosa is likely to depend at least in part on a Na+/H+ exchanger. In intestine and colon, absorption due to Na+/H+ exchanger is explained by the presence of specific isoforms of the exchanger, the NHE-3 isoform and possibly the NHE-2 isoform. The aim of the present work was to determine whether the mRNAs coding for NHE-2 and NHE-3 are expressed in epithelial cells of human gallbladder. METHODS: Total RNAs from human gallbladder were subjected to reverse transcription-polymerase chain reaction using specific primers. No message was observed with NHE-2 specific primers, showing that NHE-2 isoform plays no role in gallbladder absorption. With NHE-3 specific primers, a 239 bp cDNA fragment was obtained and showed a high homology with the NHE-3 isoform, confirming the presence of NHE-3 in the gallbladder wall. This fragment was cloned in a pLitmus vector in order to produce cRNA probes by in vitro transcription. Cellular localization of the NHE-3 mRNA was studied on cryostat sections using the cRNA probes labeled with Digoxigenin-11-UTP, controls included assays with sense probe, antibodies without probe and RNaseA treated tissue. A specific staining of the NHE-3 mRNAs was found to be strictly localized to the gallbladder epithelial cells. RESULTS/CONCLUSIONS: Expression of NHE-3 in the gallbladder was found only in the absorptive epithelial cells. The NHE-3 isoform of the Na+/H+ exchanger is likely to be involved in water and electrolyte absorption from bile.
Asunto(s)
Vesícula Biliar/metabolismo , Intercambiadores de Sodio-Hidrógeno/biosíntesis , Secuencia de Bases , Cartilla de ADN , ADN Complementario , Epitelio/metabolismo , Humanos , Hibridación in Situ , Datos de Secuencia Molecular , Membrana Mucosa/metabolismo , Reacción en Cadena de la Polimerasa , ARN Mensajero/biosíntesis , Homología de Secuencia de Ácido Nucleico , Intercambiador 3 de Sodio-Hidrógeno , Intercambiadores de Sodio-Hidrógeno/genética , Transcripción GenéticaRESUMEN
We report two cases of gastrocnemius muscle vasculitis revealing Crohn's disease. Gastrocnemius muscle biopsy evidenced a necrotizing vasculitis resembling panarteritis nodosa in one case; a nonnecrotizing vasculitis was found in the other case. Neither of the patients had systemic vasculitic involvement, and the muscle disease resembled calf muscle-located panarteritis nodosa. Our literature review shows five cases of calf-located myalgia occurring during Crohn's disease characterized by heterogenous histopathological findings including vasculitic and myositic lesions. Thus, faced with calf-located myalgia with vasculitis or myositis, a search for Crohn's disease is probably necessary to determine precisely the frequency and the etiopathogenic mechanisms of this association.
Asunto(s)
Enfermedad de Crohn/complicaciones , Músculo Esquelético/irrigación sanguínea , Vasculitis/etiología , Adulto , Biopsia , Enfermedad de Crohn/patología , Femenino , Humanos , Músculo Esquelético/patología , Vasculitis/patologíaRESUMEN
BACKGROUND/AIMS: In several studies markers of hepatitis C virus infection have been shown to be present in alcoholic patients with cirrhosis. Our work was designed to test the likely hypothesis that this association is due to an interaction between hepatitis C virus and alcohol in the pathogenesis of cirrhosis. METHODS: We compared alcohol consumption and repartition of anti-HCV antibodies detected by an immunoblot recombinant assay in 101 male patients with cirrhosis and in 120 male controls. Interactions between anti-hepatitis C virus, alcohol and cirrhosis were calculated using log linear hierarchical models for frequency data. The basis of the method is that an interaction between hepatitis C virus and alcohol implies that a model built on the hypothesis of a role of hepatitis C virus and alcohol in the disease should be improved by a coefficient associated with multiplicative effects of hepatitis C virus and alcohol. RESULTS: In patients with cirrhosis the mean alcohol consumption (148 +/- 100 g per day) and the incidence of positivity for anti-HCV antibodies (45%) were significantly higher than in controls. The results were consistent with a theoretical model built with the hypothesis of an independent role of both alcohol and hepatitis C virus. The goodness of fit between this model and the actual distribution of alcohol consumption and hepatitis C virus markers was not improved by introduction of an interaction between hepatitis C virus and alcohol. CONCLUSIONS: In alcoholic subjects with hepatitis C virus infection, the probability to have cirrhosis seemed to be explained by additive effects of alcohol and hepatitis C virus. From a purely statistical point of view, no interaction between hepatitis C virus and alcohol consumption on a multiplicative scale could be demonstrated.
Asunto(s)
Consumo de Bebidas Alcohólicas , Hepacivirus/aislamiento & purificación , Cirrosis Hepática/etiología , Probabilidad , Anciano , Estudios de Casos y Controles , Análisis Factorial , Humanos , Cirrosis Hepática/virología , Masculino , Persona de Mediana Edad , Medición de RiesgoRESUMEN
The absorption of water and electrolytes by the gallbladder seems to be largely dependent upon a Na+/H+ exchange at the apical membrane of the gallbladder epithelium. To find out if the exchanger involved is the NHE3 isoform, as in other absorbing epithelia, two studies were performed using the rabbit gallbladder. First, we studied 22Na absorption in Ussing chambers with Krebs buffer as a control solution, and in the presence of amiloride (100, 200 or 1000 microM), ethyl-isopropyl-amiloride (EIPA, 1 or 5 microM), or the phorbol ester, phorbol 12-myristate 13-acetate (PMA, 1 microM). A net mucosal-to-serosal Na+ flux was observed with control buffer. No inhibition of this net flux was observed with 5 microM EIPA, and the IC50 for amiloride was found to be 200 microM. PMA induced a reduction of absorption by 30% that was prevented by incubation with calphostin C. Resistance to amiloride and EIPA, and inhibition by PMA are consistent with the involvement of the NHE3 isoform. The second study involved reverse-transcriptase polymerase chain reaction (RT-PCR) of total gallbladder RNA, with two primers designed to amplify a 645-base-pair fragment from NHE3 mRNA. A cDNA fragment of the expected size was actually obtained from gallbladder RNA, while RT-PCR of RNA from the liver, which does not contain NHE3, gave negative results. A sequence of 492 nucleotides of the amplified product was determined, which was almost superimposable onto the known sequence of the corresponding fragment of rabbit NHE3. It is concluded that, in rabbit gallbladder, neutral NaCl absorption is, at least in part, dependent on the NHE3 isoform of the Na+/H+ exchanger.
Asunto(s)
Vesícula Biliar/metabolismo , Intercambiadores de Sodio-Hidrógeno/fisiología , Sodio/metabolismo , Absorción , Amilorida/farmacología , Animales , Secuencia de Bases , Agua Corporal/metabolismo , ADN Complementario/metabolismo , Electroforesis en Gel de Agar , Inhibidores Enzimáticos/farmacología , Datos de Secuencia Molecular , Naftalenos/farmacología , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Conejos , Intercambiadores de Sodio-Hidrógeno/genética , Acetato de Tetradecanoilforbol/farmacologíaRESUMEN
1. In man and in various animal species, absorption of NaCl from bile by the gallbladder mucosa is associated with luminal proton secretion. A similar absorption of NaCl in small intestine, colon and renal tubule is related, at least in part, to the presence of the NHE3 isoform of the Na+/H+ exchanger. This work was designed to find out whether NHE3 is also present in human gallbladder. 2. At surgery, 100-200 mg of the gallbladder wall was obtained from patients treated by cholecystectomy for gallstones. After isolation of the mucosa, total RNA was extracted and submitted to reverse transcription-polymerase chain reaction with two primers: 5'-AAGCCICTGGTGCAGTGGCTGAAGG-3' and 5'-GGAGTCCTTIAAGTCGGCIAAGCTGGGC-3', designed to amplify a sequence of 645 bp of rabbit NHE3 mRNA (642 bp in man). RNA from human liver and from rabbit heart, neither of which contain NHE3, and human ileal RNA, which does contain NHE3, were used as controls. 3. RNA extracted from the mucosal moiety of the gallbladder wall gave an amplification product of about 645 nucleotides. Controls gave the expected negative or positive results. Sequencing of the amplified RNA showed it was almost identical to previously determined sequences of NHE3 in other human tissues. 4. It is concluded that the mucosa of human gallbladder contains the mRNA of NHE3 isoform. This isoform could therefore play a role in sodium absorption from bile.
Asunto(s)
Vesícula Biliar/química , ARN Mensajero/análisis , Intercambiadores de Sodio-Hidrógeno/análisis , Animales , Secuencia de Bases , Cartilla de ADN/genética , ADN Circular/genética , Electroforesis en Gel de Agar , Humanos , Íleon , Mucosa Intestinal/química , Datos de Secuencia Molecular , Membrana Mucosa/química , Reacción en Cadena de la Polimerasa , Conejos , Intercambiadores de Sodio-Hidrógeno/genéticaRESUMEN
BACKGROUND/AIMS: In a previous study, we reported that in cultured rat hepatocytes, ethanol inhibits intercellular communication which is known to play a central role in the regulation of cell growth and differentiation. This work was designed to find out if ethanol exerts a direct action on cell membranes, comparable to other long-chain (C6-C9) alcohols, or an indirect action. METHODS: Intercellular communication was measured on short-term cultured rat hepatocytes by the fluorescent Lucifer-Yellow CH transfer method. Intracellular pH was measured by spectrofluorimetry and membrane expression of connexin 32 by indirect immunofluorescence. RESULTS: Under our conditions, ethanol (20 mM) inhibited intercellular communication of hepatocytes to the same extent as did octanol and 1 mM. Immunofluorescence semi-quantitative studies of connexin 32 suggested that the observed inhibition was not related to a decrease in the number of gap junction plaques. In contrast with those of octanol, the inhibitory effects of ethanol appeared to be indirect because the inhibition of ethanol metabolism by 4-methyl pyrazole abolished its effects on intercellular communication, while 4-methyl pyrazole did not influence the effects of octanol. Acetaldehyde, the main metabolite of ethanol was without effect on gap junctions. CONCLUSIONS: This suggests that the inhibition of intercellular communication induced by ethanol may be included among the consequences of intermediary cell metabolism disturbances indirectly due to ethanol oxidation. This may be one of the mechanisms by which ethanol metabolism exerts a hepatotoxic possibly carcinogenic action.
Asunto(s)
Comunicación Celular/efectos de los fármacos , Depresores del Sistema Nervioso Central/farmacología , Etanol/farmacología , Uniones Comunicantes/efectos de los fármacos , Hígado/citología , 1-Octanol , Acetaldehído/farmacología , Animales , Membrana Celular/metabolismo , Células Cultivadas , Conexinas/efectos de los fármacos , Conexinas/metabolismo , Técnica del Anticuerpo Fluorescente Indirecta , Colorantes Fluorescentes , Fomepizol , Concentración de Iones de Hidrógeno , Isoquinolinas , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Microscopía Electrónica , Octanoles/farmacología , Pirazoles/farmacología , Ratas , Ratas Sprague-Dawley , Espectrometría de Fluorescencia , Proteína beta1 de Unión ComunicanteRESUMEN
The finding of a high PCO2 in basally secreted pancreatic juice of man and dog raises the hypothesis of proton secretion from ductal epithelial cells presumably through a Na+/H+ exchanger. To test this possibility, H+ luminal secretion and Na+ movements were measured in vitro on samples of bovine pancreatic ducts mounted in Ussing-type chambers. The rate of luminal acidification measured by the pH stat method, using bicarbonate-free media gassed with 100% O2, reached 2.75 muEq/cm2/hr. Proton secretion was blocked in the presence of 1 nM amiloride or in the absence of Na+ (replaced by choline) in the mucosal solution. Study of transepithelial 22Na fluxes in short-circuited tissue, bathed on both sides by control Ringer solution, gassed by 95% O2-5% CO2 demonstrated a net sodium transport from the mucosal to the interstitial side of the duct (net 22Na flux = 3.23 +/- 0.8 muEq/cm2/hr). This net sodium transport was electroneutral and blocked by mucosal amiloride (0.5-1 mM/liter) or by interstitial ouabain (1 mM/liter). These results are consistent with the existence of a Na+/H+ exchanger on the luminal side of the bovine main pancreatic duct.
Asunto(s)
Conductos Pancreáticos/metabolismo , Intercambiadores de Sodio-Hidrógeno/metabolismo , Amilorida/farmacología , Animales , Bovinos , Técnicas In Vitro , Nistatina/farmacología , Ouabaína/farmacología , Sodio/metabolismo , Intercambiadores de Sodio-Hidrógeno/antagonistas & inhibidoresAsunto(s)
Enfermedades del Conducto Colédoco/complicaciones , Enfermedades de la Vesícula Biliar/complicaciones , Vesícula Biliar/anomalías , Anciano , Colangiografía , Colecistografía , Enfermedades del Conducto Colédoco/diagnóstico por imagen , Enfermedades del Conducto Colédoco/cirugía , Dilatación Patológica , Endoscopía del Sistema Digestivo , Vesícula Biliar/patología , Vesícula Biliar/cirugía , Enfermedades de la Vesícula Biliar/diagnóstico por imagen , Enfermedades de la Vesícula Biliar/patología , Enfermedades de la Vesícula Biliar/cirugía , Humanos , MasculinoRESUMEN
We report the first case of probable protein-losing enteropathy revealing a cytomegalovirus/Yersinia enterolytica infection at the onset of a chronic lymphocytic leukaemia. Severe hypoprotidaemia, digestive tract yersiniosis, ulcerative and microgranulomatous enteritis with a large number of cytomegalic inclusions in mucosal cells, and incipient lymphoid proliferation were the most characteristic findings.
Asunto(s)
Infecciones por Citomegalovirus/complicaciones , Enteritis/complicaciones , Leucemia Linfocítica Crónica de Células B/complicaciones , Enteropatías Perdedoras de Proteínas/etiología , Yersiniosis/complicaciones , Anciano , Terapia Combinada , Infecciones por Citomegalovirus/patología , Infecciones por Citomegalovirus/cirugía , Infecciones por Citomegalovirus/virología , Enteritis/microbiología , Enteritis/patología , Enteritis/terapia , Humanos , Masculino , Combinación Trimetoprim y Sulfametoxazol/uso terapéutico , Yersinia/aislamiento & purificación , Yersiniosis/tratamiento farmacológico , Yersiniosis/microbiologíaRESUMEN
Watermelon stomach is a rare disorder causing gastric blood loss and iron deficiency anemia. We report a case that occurred during the course of post-hepatitis C cirrhosis, which condition was dramatically improved by alpha-interferon treatment.
Asunto(s)
Hepatitis C/terapia , Interferón-alfa/uso terapéutico , Gastropatías/patología , Anciano , Femenino , Hepatitis C/complicaciones , Humanos , Gastropatías/complicacionesRESUMEN
Calcium concentration of pancreatic juice depends on secretion of calcium bound to enzymatic proteins or calcium diffusion from interstitial fluids. To evaluate the relative magnitude of these pathways, we studied the influence of hypercalcemia on ionized calcium (Ca++) in dog pancreatic juice. Pancreatic juice was collected during basal secretion and during stimulation by secretin or secretin plus caerulein in control conditions and under CaCl2 infusion. [Ca++] was measured by selective electrodes. Saturation of juice in CaCO3 was calculated. In stimulated juice, total calcium concentration ([CaT]) and [Ca++] were unchanged by hypercalcemia. In basal juice, composition was profoundly modified by hypercalcemia because [CaT] (3.31 +/- 0.89 mmol/L vs 1.80 +/- 0.44 for controls), [Ca++] (1.44 +/- 0.37 mmol/L vs 0.84 +/- 0.24 mmol/L for controls), and the index of saturation in CaCO3 (5.2 +/- 2.4 vs 2.9 +/- 1.8 for controls) increased significantly. Protein concentration was unchanged. This suggests that in basal conditions, the relationship between plasma and juice calcium levels is due to passive interstitial Ca++ diffusion through the pancreatic ducts. In accordance with the hypothesis of a restricted calcium diffusion, the effects of hypercalcemia were flow rate dependent, being less pronounced when basal flow rate increased. It is concluded that, in the dog, the calcium species found in stimulated juice result from a redistribution of calcium secreted along with proteins, whereas at low secretion rate, juice calcium level depends mainly on interstitial Ca++ diffusion into the main pancreatic ducts.
Asunto(s)
Calcio/metabolismo , Hipercalcemia/metabolismo , Jugo Pancreático/metabolismo , Análisis de Varianza , Animales , Cationes Bivalentes/metabolismo , Ceruletida , Perros , Eritritol/metabolismo , Espacio Extracelular/metabolismo , SecretinaRESUMEN
In this study, the authors report two observations of granulomatous hepatitis. The secondary appearance of a mononucleosis syndrome, three weeks after the onset of fever, in healthy adults, evoked the diagnosis of a cytomegalovirus infection. The authors insist on the histologic and virologic differences of the CMV infection between the healthy adults and the immunodepressed patients. They also note the difficulties of the diagnosis of the CMV infection in healthy adults.
Asunto(s)
Infecciones por Citomegalovirus/complicaciones , Granuloma/etiología , Mononucleosis Infecciosa/etiología , Hepatopatías/etiología , Adulto , Anciano , Infecciones por Citomegalovirus/diagnóstico , Femenino , Empleos en Salud , Humanos , Síndromes de Inmunodeficiencia/complicaciones , Masculino , Exposición Profesional , SíndromeAsunto(s)
Hepatitis C/terapia , Hepatitis Crónica/terapia , Interferón-alfa/efectos adversos , Liquen Plano/inducido químicamente , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Interferón-alfa/administración & dosificación , Interferón-alfa/uso terapéutico , Persona de Mediana Edad , Factores de TiempoRESUMEN
In several species, bicarbonate and calcium concentrations of pancreatic juice are known to vary during the different phases of pancreatic secretion. The effects of these variations on the saturation of juice with calcium carbonate, a critical factor for the formation of pancreatic stones, are not known. In this work, we studied the saturation degree of pancreatic juice with calcium carbonate in six unanesthetized beagle dogs equipped with Thomas cannulae during basal secretion and after bolus injections of cerulein (30 ng/kg) or secretin (0.25 units/kg). In the different samples of pure pancreatic juice, pH, PCO2, bicarbonate, and proteins were measured by standard methods. Total calcium (CaT) and ionized calcium (Ca2+) were determined using calcium-specific electrodes. Saturation with calcium carbonate was calculated by reference to the solubility product of calcite at 37 degrees C. Almost all the samples were found to be supersaturated with calcium carbonate but large variations of the saturation index were observed. In basal samples, obtained during periods of low secretion rate, the mean saturation index (3.35 +/- 3.01) was significantly lower than under secretion (12.10 +/- 5.14) or cerulein (18.01 +/- 8.42). This low basal saturation index, in spite of a high Ca2+ content, was explained by a low bicarbonate concentration (37.6 +/- 18.9 mmol/liter) and a high PCO2 (13.4 +/- 7.5 kPa). In contrast, in juice obtained after hormonal stimulation, PCO2 (4.8 +/- 1.6 kPa) was similar to plasma PCO2 (5.5 +/- 1.2 kPa).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Carbonato de Calcio/metabolismo , Cálculos/etiología , Enfermedades Pancreáticas/etiología , Conductos Pancreáticos/metabolismo , Jugo Pancreático/química , Animales , Cálculos/química , Ceruletida/farmacología , Perros , Enfermedades Pancreáticas/metabolismo , Jugo Pancreático/metabolismo , Secretina/farmacología , Factores de TiempoRESUMEN
Little is known of the effects of meal composition on gallbladder emptying and cholecystokinin (CCK) release in man. Gallbladder volumes (measured by means of real time ultrasonography) and plasma CCK levels (determined by radioimmunoassay) were studied in 5 normal subjects, before and after a normal solid-liquid meal, and before and after a low-fat, low-protein, solid-liquid meal after 3 days regimen with low-fat, low-protein meal. Low-fat, low-protein regimen significantly increased gallbladder fasting volume and significantly decreased fasting plasma CCK levels. This suggests that CCK secretion regulates fasting gallbladder volume and that basal CCK secretion depends on diet composition. After a normal meal, gallbladder emptying was biphasic with a 44% volume decrease within the first 15 min followed by slower emptying during the next 60 min with a final volume reaching less than 15% of the fasting volume. After a hypolipidic, hypoproteic meal, the initial 15 min emptying (42%) was the same as after control meals but no further decrease of gallbladder volume was observed. This study shows that the initial phase of post prandial gallbladder contraction is not dependent on meal composition which affects late gallbladder emptying only. We conclude that a low-fat, low-protein diet, increasing gallbladder fasting volume and decreasing gallbladder emptying, may favor gallbladder stasis and therefore increase the risk of gallstone formation.
Asunto(s)
Colecistoquinina/metabolismo , Grasas de la Dieta/administración & dosificación , Proteínas en la Dieta/farmacología , Vaciamiento Vesicular/fisiología , Colecistoquinina/análisis , Dieta , Ayuno , Vaciamiento Vesicular/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Radioinmunoensayo , Valores de ReferenciaRESUMEN
Several studies suggest that bile salts are transported from the basolateral to the canalicular membrane of hepatocytes by a vesicular pathway, possibly in part via the Golgi complex. To test this hypothesis, the present study examined, in the perfused rat liver, the influence of the Na+ ionophore monensin on the biliary secretion of taurocholate and biliary lipids. The effects of the drug have been checked by the study of the ultrastructural modifications of the Golgi complex, secretion of horseradish peroxidase, and bile salt uptake. An infusion of monensin (1, 3, or 5 mumol/L) into the liver induced considerable swelling of the Golgi complex within 5 minutes. After a bolus injection of horseradish peroxidase during monensin infusion, the biliary secretion of the protein was delayed (1 mumol/L monensin) and markedly reduced (5 mumol/L monensin). Bile salt uptake was virtually unchanged except with 5 mumol/L monensin. This suggests that monensin has the same effects on the subcellular traffic in the perfused liver as in cultured cells. After a bolus injection of taurocholate (0.25, 5.0, or 8.5 mumol/100 g body wt) during monensin infusion, the pattern of biliary secretion of the bile salt was identical to that of controls. During continuous infusion of taurocholate, a 10-minute monensin infusion (1 or 3 mumol/L) had no effect on the biliary secretion of taurocholate and on the secretion of lecithin and cholesterol induced by taurocholate. High concentrations (5 mumol/L) or prolonged infusions (20 minutes) of monensin decreased the biliary secretion of bile salts but corresponded to a marked decrease of taurocholate uptake. In summary, the Na+ ionophore monensin altered the Golgi complex and the vesicular transport of horseradish peroxidase, whereas taurocholate biliary secretion was not influenced unless taurocholate biliary secretion was not influenced unless taurocholate uptake by the liver was markedly decreased. It may be concluded that taurocholate and biliary lipid secretion, under these conditions, does not depend essentially on pathways involving acidic transporting vesicles and particularly the trans-Golgi complex.
Asunto(s)
Ácidos y Sales Biliares/metabolismo , Aparato de Golgi/efectos de los fármacos , Hígado/efectos de los fármacos , Monensina/farmacología , Animales , Transporte Biológico , Aparato de Golgi/fisiología , Peroxidasa de Rábano Silvestre/metabolismo , Hígado/metabolismo , Masculino , Perfusión , Ratas , Ratas EndogámicasRESUMEN
The formation of intracellular lumina with apical differentiation is observed in several cancerous epithelial cell lines including human hepatocarcinoma. This disorder of cell polarization can be induced by the inhibition of cell-cell communication, a known factor of carcinogenesis. This work was designed to study the effects of ethanol on the differentiation of hepatocytes in short-term culture. Isolated hepatocytes were plated on plastic culture dishes that were 35 mm in diameter (10(6) cells/dish). Three hours after plating, the hepatocytes were incubated in the presence of 20 mmol/L ethanol for 1 hr. Treated cells were compared with controls using morphometric methods after conventional treatment for ultramicroscopy and by measuring cellular dye coupling by the fluorescent Lucifer Yellow CH transfer method. Bile canaliculi formation decreased in alcohol-treated cells (6.5% vs. 9.9%, 2p less than 0.05), whereas intracellular lumina incidence increased (3.1% vs. 0.5%, 2p less than 0.01). In parallel, the dye-coupling capacity decreased significantly when hepatocytes were treated with alcohol (2p less than 0.01). This work shows that short-term ethanol treatment induces significant disturbances of cell polarization and inhibits the reestablishment of cell-cell communication in cultured hepatocytes. These disorders could, at least in part, explain the carcinogenic effects of ethanol.
Asunto(s)
Comunicación Celular/efectos de los fármacos , Polaridad Celular/efectos de los fármacos , Etanol/farmacología , Hígado/citología , Animales , Canalículos Biliares/diagnóstico por imagen , Células Cultivadas , Hígado/ultraestructura , Masculino , Ratas , Ratas Endogámicas , Factores de Tiempo , UltrasonografíaRESUMEN
Samples of gallbladder bile obtained from 25 controls and 34 patients with pigment (28 cases) or cholesterol (6 cases) gallstones were studied to establish whether disturbances in regulation of the biliary pH are likely to play a role in the pathogenesis of gallstones. Samples were assayed for pH, PCO2 and concentrations of sodium, bicarbonate and calcium (total and ionized). Saturation of bile in calcium carbonate was calculated. The main results of the study were as follows: (a) mean (+/- S.D.) PCO2 was significantly higher in gallbladder bile (6.72 +/- 0.36 kPa (in controls) and 7.63 +/- 0.29 kPa in patients) than in blood. This is consonant with previous results in animal species; it suggests that also in man a mucosal Na+ H+ antiport acidifies the gallbladder bile generating CO2 from biliary bicarbonate. (b) Biliary pH decreased when sodium concentration increased over a range of 140 to 280 mM. The pH decreased slightly when sodium increased from 140 to 200 mM and rapidly beyond this value; the rapid pH decrease in concentrated bile was associated with bicarbonate concentrations lower than 1 to 2 mM. The results showed that bicarbonate is the main buffer of gallbladder bile. (c) The pH decrease during bile concentration was similar in patients and controls. In both groups, fully concentrated bile was unsaturated in calcium carbonate. The results suggest that gallstone formation is not due to disturbances of biliary pH regulation. However, the normal concentration process that increases Ca++ concentration up to 4 mM and lowers pH values is likely to favor, in fully concentrated biles, the precipitation of calcium salts such as calcium bilirubinate.