RESUMEN
OBJECTIVES: Human colostrum is known to be important for the protection of infants against infection by pathogenic microorganisms. This protection is thought to be due, partially, to various neutral and acidic oligosaccharides that are present in colostrum and milk. However, the concentrations of each of the oligosaccharide of human colostrum have not yet been determined. The aim of this present study was to determine the concentration of each of the major neutral oligosaccharide for three consecutive days from the start of lactation. METHOD: We analyzed the level of each neutral oligosaccharide in human colostrum, for three consecutive days from the start of lactation, obtained from 12 healthy Japanese women (ranging in age from 21 to 35 years; primipara 6 and multipara 6). The ABO blood groups of the donors were determined: A, three; B, three; O, five; AB, one. The determined human milk oligosaccharides were 2'-fucosyllactose (2'-FL), 3-fucosyllactose (3-FL), lactodifucotetraose (LDFT), lacto-N-tetraose (LNT), lacto-N-neotetraose (LNnT), three lacto-N-fucopentaose (LNFP I, II and III) and two lacto-N-difucohexaose (LNFDH I and II) using high-performance liquid chromatography (HPLC) with two derivatization techniques. RESULTS: The concentrations of 2'-FL and LDFT in colostrum on day 1 were significantly higher than those on days 2 and 3 (P<0.05). An increase in LNT was observed on day 3 compared with day 1 (P<0.05). CONCLUSION: These changes in concentrations of 2'-FL, LDFT and LNT may reflect the requirements for prebiotics and anti-infection agents by human infants during early lactation.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Calostro/química , Lactancia/metabolismo , Oligosacáridos/análisis , Adulto , Femenino , Humanos , Paridad , Periodo Posparto/metabolismo , Embarazo , Factores de TiempoRESUMEN
BACKGROUND: Although liver transplantation has become a standard therapy for diseases such as fulminant hepatitis and cirrhosis, the lack of donor organs remains a major problem. One solution is the development of transplantable hepatocytes. The metabolic characteristics as well as function and adaptation of hepatocytes (R-EES-hep cell) derived from rat early embryonic stem cells were examined after transplantation into rats with surgically induced liver failure. METHODS: Rat hepatocyte cell lines were established from early embryonic stem cells cultured in the presence of embryotrophic factors by colony cloning methods. The cell lines were established from two cell embryos taken from spontaneous dwarf rats using the novel method of Ishiwata et al. Morphologic differentiation as well as albumin and bilirubin production were observed by immunostaining. R-EES-hep cells were transplanted into the spleens of 90% hepatectomized, surgically induced liver failure rats to analyze survival rates. RESULTS: When cultured in type I collagen gel the cells formed cordlike structures resembling the liver. Both albumin and bilirubin production were observed when transplanted; the spleen was converted into a liver-like structure with prolonged survival of the 90% hepatectomized rats for up to 3 months up to the time of killing. CONCLUSIONS: R-EES-hep cells showed many of the distinctive metabolic characteristics of the liver. These cells may be efficient for further research and application for hepatic cell transplantation to treat liver insufficiency patients and as biologic artificial organs.
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Hepatocitos/citología , Hepatocitos/trasplante , Fallo Hepático/terapia , Trasplante de Células Madre , Animales , Línea Celular , Hepatectomía , Hepatocitos/metabolismo , Hígado/cirugía , Hepatopatías , Fallo Hepático/etiología , Hígado Artificial , Masculino , Ratas , Ratas Sprague-Dawley , Células MadreRESUMEN
In previous studies, we showed that pretreatment of rat FRTL-5 thyroid cells with TSH, or other agents that increased intracellular cAMP, markedly potentiated DNA synthesis in response to insulin-like growth factor-I (IGF-I). In addition, we found that TSH pretreatment caused an increase in tyrosine phosphorylation of intracellular proteins including an unidentified 125-kDa protein that was well correlated with the TSH-potentiating effect on DNA synthesis induced by IGF-I. These results suggested that cAMP amplified IGF-I-dependent signals for cell growth through changes of cAMP-dependent tyrosine phosphorylation. The present studies were undertaken to determine how tyrosine kinase activation followed by an increase in tyrosine phosphorylation is required for cAMP-dependent potentiation of DNA synthesis induced by IGF-I in this cell line. First of all, we measured tyrosine kinase or protein-tyrosine phosphatase activities in the cell lysates by the in vitro assay. Chronic treatment with TSH or (Bu)2-cAMP stimulated tyrosine kinase activity in the particulate fraction and protein-tyrosine phosphatase activity in the soluble fraction, suggesting that tyrosine kinase plays more important roles for a cAMP-dependent increase in tyrosine phosphorylation of intracellular proteins. The increased tyrosine kinase activity was sensitive to genistein, a potent tyrosine kinase inhibitor. Genistein abolished both the cAMP-dependent increase in tyrosine phosphorylation of the 125-kDa protein and the enhanced DNA synthesis induced by IGF-I in a similar concentration-dependent manner. The only tyrosine-phosphorylated protein associated with the p85 regulatory subunit of phosphatidylinositol (PI) 3-kinase in response to cAMP was 125 kDa. In addition, we found that PI 3-kinase activity bound to p85 subunit significantly increased after (Bu)2cAMP treatment. These results suggested that cAMP stimulates PI 3-kinase through tyrosine phosphorylation of the 125-kDa protein. We then measured DNA synthesis in cells pretreated for 24 h with TSH or (Bu)2cAMP in the absence or presence of LY294002, a PI 3-kinase inhibitor, followed by treatment with IGF-I for 24 h. Presence of LY294002 during TSH or (Bu)2cAMP pretreatment completely abolished cAMP-dependent potentiation of DNA synthesis induced by IGF-I. These results suggest that in FRTL-5 cells cAMP activates genistein-sensitive tyrosine kinases that in turn activate PI 3-kinase activity. These mechanisms appear to be necessary for cAMP-dependent potentiation of the DNA synthesis induced by IGF-I.
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AMP Cíclico/fisiología , ADN/biosíntesis , Factor I del Crecimiento Similar a la Insulina/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Animales , Bucladesina/farmacología , Línea Celular , Cromonas/farmacología , Sinergismo Farmacológico , Activación Enzimática/fisiología , Inhibidores Enzimáticos/farmacología , Genisteína/farmacología , Isoenzimas/metabolismo , Morfolinas/farmacología , Fosfoproteínas/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Tirosina Fosfatasas/metabolismo , Ratas , Vanadatos/farmacologíaRESUMEN
A prospective study was conducted in 71 evaluable patients who received myeloablative hematopoietic stem cell transplantation (HSCT) at our facility from 1995 to 2002, to find a sensitive marker for post-transplant heart failure, including echocardiographic systolic and diastolic markers and QTc interval. QTc was found to be an independent and significant risk factor for acute heart failure (AHF) on multivariate logistic regression analysis (OR 1.5, P=0.01, 95% confidence interval (CI) 1.1-2.0), while no significant differences between patients with AHF and those without AHF were found in age, sex, treatment history, type of conditioning regimen, and echocardiographic systolic and diastolic markers. On further analysis, post-transplant risk of AHF appeared to be increased as QTc was prolonged. The post-transplant risk of AHF in the group with longest QTc on multivariate logistic regression analysis was found to be 9.8 times that in the group with shortest QTc (P=0.04, 95% CI 1.0-100). These results suggest that echocardiographic markers are less valuable predictors of post-transplant AHF, but that prolongation of the QTc, an ECG marker, before HSCT is strongly associated with onset of AHF after HSCT.
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Electrocardiografía , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Agonistas Mieloablativos/efectos adversos , Enfermedad Aguda , Adulto , Biomarcadores , Diástole , Femenino , Insuficiencia Cardíaca/epidemiología , Humanos , Síndrome de QT Prolongado/diagnóstico , Síndrome de QT Prolongado/epidemiología , Síndrome de QT Prolongado/etiología , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Estudios Prospectivos , Factores de Riesgo , SístoleRESUMEN
To establish the baseline data, age-related changes and the regional expression of the hepatic P450 isozymes in Syrian hamsters of the APA strain at 3, 6, 12, 18 months old were examined by immunological techniques. Immunohistochemical analysis of liver serial sections revealed that the midzonal and perivenous regions (zones 2 and 3, respectively) were stained with the anti-rat CYP1A1/2, 2B1/2 and 2E1 antibodies. These three antibodies most intensely stained the hepatocytes around the central vein. An anti-rat CYP3A2 staining section had a staining pattern with equally intense reactions in zones 2 and 3. On the other hand, CYP2C6, 2C11 and 4A1 were distributed diffusely throughout the hepatic acinus. There was no age-related difference in the expression pattern of any of the P450 isozymes examined. Total P450 content had a peak at 6 months of age and decreased to 60% of that level thereafter. Western-blot analysis revealed that the peak expressions of the isozymes detected with anti-rat CYP1A1/2, 2C6, 2E1 and 3A2 antibodies were observed in 6-month-old hamsters and declined in older ones. The CYP2B and 2C11 content reached the maximum at the age of 6 months and maintained almost the same level thereafter. The CYP4A level did not change from 3 to 6 months, and then declined to about 40% of the younger level at 12 and 18 months of age. These results suggest that the hepatic P450 isozymes of APA hamsters have region-specific expressions and most isozymes have their peaks of expression at 6 months of age, which differs from the patterns for rat P450.
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Envejecimiento/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Hígado/enzimología , Mesocricetus/fisiología , Animales , Western Blotting , Peso Corporal/fisiología , Cricetinae , Inmunoquímica , Inmunohistoquímica , Isoenzimas , Masculino , Microsomas Hepáticos/enzimología , Tamaño de los Órganos/fisiologíaRESUMEN
The effects of food, antibiotics, diclofenac sodium (DS) and methotrexate (MTX) on oral bioavailability (BA) of MTX were examined in rats. Feeding didn't vary the plasma concentrations after intravenous dosing of 0.5 mg/kg MTX, but enhanced those after oral dosing, and the oral BA. The twice daily oral doses of 40 mg/kg neomycin sulfate (NS) or mixed antibiotics (200 mg/kg NS + 200 mg/kg streptomycin sulfate + 200 mg/kg bacitracin) for 5 days didn't influence the plasma concentrations after intravenous dosing of 0.5 mg/kg MTX, but induced the decreased Cmax and the delayed MRT after oral dosing. The plasma concentrations after intravenous or oral dosing of 2.5 mg/kg MTX in rats orally dosed with 1 or 5 mg/kg/day DS for 4 days were similar to those in the control rats, while the pre-treatment of 25 mg/kg/day DS delayed the elimination of MTX but didn't change the oral BA. The plasma concentrations after intravenous or oral dosing of 2.5 mg/kg MTX in rats, which received the intermittent oral doses of 7.5 mg/kg/3 doses/week MTX for 4 weeks, were comparable to those in the control rats, but the daily pre-treatment of 0.2 mg/kg/day MTX for 4 weeks increased the plasma concentrations after oral dosing, and the BA.
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Antimetabolitos Antineoplásicos/farmacocinética , Metotrexato/farmacocinética , Administración Oral , Animales , Antibacterianos/farmacología , Antiinflamatorios no Esteroideos/farmacología , Antimetabolitos Antineoplásicos/administración & dosificación , Disponibilidad Biológica , Diclofenaco/farmacología , Ayuno , Vaciamiento Gástrico/efectos de los fármacos , Metotrexato/administración & dosificación , Ratas , Ratas Sprague-DawleyRESUMEN
In this paper, the experimental validation of a combined electromagnetic and thermal model for a microwave drying of capillary porous materials inside a rectangular wave guide is presented. The effects of the irradiation time, particle sizes and the variation of initial moisture content on the microwave drying kinetics are clarified in detail, considering the interference between incident and reflected waves in the capillary porous materials. The established model has allowed us to determine the space-time evolution of electric field, temperature and moisture content within capillary porous materials during microwave drying process.
RESUMEN
Diagnosis of fungal infections in compromised hosts has been difficult because of insufficient sensitivity and specificity of conventional methods such as culturing and serum testing. Therefore, antifungal agents are usually started in febrile patients who are resistant to antibiotics even if these monitoring tests were negative. In this study, therefore, in order to increase the reliability of these monitoring, polymerase chain reaction (PCR) methods for detection of blood fungus were also performed in compromised hosts including 14 patients with hematological malignancies and one with solid tumor who were undergoing chemotherapies. From these patients, total of 56 peripheral blood samples was collected periodically, irrespective of the presence of infectious signs. At each time point of venopuncture, status of the patient was allocated to one of the followings: A, receiving an intravenous antifungal therapy because of sustaining fever which had not responded to prior antibiotic therapies and also positive for culturing and/or serum beta-D-glucan tests; B, receiving an additional intravenous antifungal therapy but negative for culturing and serum-tests; C, febrile but not yet receiving any intravenous fungal therapy; D, afebrile status. During the study, 10 blood samples from 3 patients were allocated in group A, and one sample of them was positive while remaining 9 were all negative for PCR. Six samples from 4 patients were in group B, and one was PCR positive while remaining 5 were negative. Fifteen samples from 7 patients were in group C, and 3 were positive and 12 were negative for PCR. Twenty-five samples were in group D, and 5 were positive and 20 were negative for PCR. Thus, the results from fungal PCR in these patients were in some case showed discrepancies from those expected from the clinical course and/or conventional monitoring tests. Further evaluation of fungal PCR may gain insight into the more precise diagnosis of fungal infection in these patients.
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Huésped Inmunocomprometido , Micosis/diagnóstico , Infecciones Oportunistas/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Adulto , Femenino , Hongos/aislamiento & purificación , Neoplasias Hematológicas/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Micosis/complicaciones , Micosis/microbiología , Infecciones Oportunistas/complicaciones , Infecciones Oportunistas/microbiologíaRESUMEN
The acquired coagulation factor inhibitors are classified into alloantibodies, which appear in association with supplementary treatment for congenital coagulation factor deficiency, and autoantibodies, which are spontaneously produced. We report here 2 cases of acquired factor VIII inhibitor and 1 case of factor V inhibitor. Case 1: A 52-year-old woman noted swelling of the right parotid region in March 1988. Though contrast examination was scheduled, she was admitted for detailed examination due to a markedly prolonged coagulation time. An APTT correction test suggested that decreased factor VIII activity was due to the presence of an inhibitor. Since antinuclear antibody and SS-A antibody were positive and infiltration by lymphocytes in the salivary gland acini in a lip biopsy specimen was detected, Sjögren's syndrome was diagnosed. Case 2: A 33-year-old woman had normal delivery of her second child in February 1998. In June 1998, she suffered slight contusion in the left lower limb. The affected site became swollen and painful, making walking difficult. Since both upper limbs became markedly swollen after 1 week, she visited our hospital. Prolonged APTT and a marked decrease in factor VIII activity were observed. Factor VIII inhibitor titer was high at 19 Bethesda units. Case 3: A 64-year-old man had had asymptomatic macroscopic hematuria since the beginning of August 1998 but was placed under observation since no abnormal findings were observed on various imaging tests. However, he was admitted to Osaka City General Medical Center because of vesicular tamponade. Factor V activity was markedly decreased to 1.0%. PT correction test suggested that decreased factor V activity was due to the presence of an inhibitor. The underlying disease could not be determined in this case. In patients with acquired coagulation inhibitors, bleeding symptoms are reported to be mild in many cases, and severe bleeding is rare. However, cases of death without severe bleeding or underlying disease have also been reported, indicating that the prompt diagnosis and treatment of this condition are necessary.
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Inhibidores de Factor de Coagulación Sanguínea/sangre , Trastornos Hemorrágicos/etiología , Adulto , Autoanticuerpos/sangre , Factor V/análisis , Factor V/inmunología , Factor VIII/análisis , Factor VIII/inmunología , Femenino , Trastornos Hemorrágicos/sangre , Humanos , Inmunoglobulina G/sangre , Isoanticuerpos/sangre , Masculino , Persona de Mediana Edad , Tiempo de Tromboplastina ParcialRESUMEN
A 33-year-old woman who had been healthy and had no history of abnormal bleeding developed widespread ecchymoses and intramuscular bleeding 4 months after her second delivery. On admission, laboratory examination data revealed that factor VIII activity was markedly reduced (4%) and APTT was prolonged (119.7s). Factor VIII inhibitor titer was high, at 19 Bethesda units. Her chemical and serological data were normal. No antinuclear antibodies were detected. We concluded that factor VIII inhibitor had been spontaneously produced after the second delivery and was responsible for her bleeding tendency. Prednisolone (60 mg/day) and factor VIII concentrates were administered to stop the bleeding, but factor VIII activity did not increase while factor VIII inhibitor titer increased to 29 Bethesda units. Therefore, treatment with factor VIII concentrate (was stopped while prednisolone was continued resulting in reduction of factor VIII inhibitor titer and improvement of her bleeding tendency. At 8 months after admission, factor VIII inhibitor titer was not detected by the Bethesda method and factor VIII activity and APTT were normal.
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Factor VIII/antagonistas & inhibidores , Embarazo/fisiología , Adulto , Femenino , Hemorragia/etiología , HumanosRESUMEN
A case of asynchronous triple cancer in an 88-year-old male is reported. Six years ago, he had received left radical nephrectomy for renal cell carcinoma, and 2 years ago partial hepatectomy for hepatocellular carcinoma detected by follow-up computed tomography (CT). During the post-operative follow-up, no metastasis of either the renal or hepatic carcinoma was detected. On February 12, 1997 he presented with macroscopic hematuria. Cystoscopy revealed a tumor emerging from the left ureteral orifice, while CT and magnetic resonance imaging (MRI) revealed a tumor mass in the left exterior of bladder. Diagnosis of residual ureter tumor, we performed both left ureterectomy and partial cystectomy. Histological diagnosis revealed transitional cell carcinoma of the residual ureter (G2 > G3, pT1, pV0, pL0, pR0). Convalescence was uneventful and 10 months after the operation, he is alive with no recurrence or metastasis. We stress the importance of careful follow-up not only to perceive the recurrence or metastasis of renal cancer but also to detect cancer in other parts of the body.
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Carcinoma Hepatocelular/patología , Carcinoma de Células Renales/patología , Carcinoma de Células Transicionales/patología , Neoplasias Renales/patología , Neoplasias Hepáticas/patología , Neoplasias Primarias Múltiples , Neoplasias Ureterales/patología , Anciano , Anciano de 80 o más Años , Carcinoma de Células Renales/cirugía , Humanos , Neoplasias Renales/cirugía , Masculino , Neoplasia Residual , NefrectomíaRESUMEN
Liver damage induced by lipopolysaccharide (LPS) in actinomycin D-sensitized mice was initiated by a Fas/CD95-independent apoptotic process that produced DNA fragmentation in hepatocytes followed by an increase of plasma ALT. The metabolic inhibitor actinomycin D blocked most of the LPS-induced increase of plasma nitrite/nitrate levels, as did administration of a nitric oxide synthase inhibitor, N(G)-monomethyl-l-arginine, which also promoted LPS-induced apoptotic liver damage. Administration of nitric oxide donors (hydroxylamine, S-nitroso-N-acetylpenicillamine or 2, 2'-(hydroxynitrosohydrazino)bis-ethanamine) resulted in elevation of the plasma nitrite/nitrate level and amelioration of actinomycin D/LPS-induced apoptotic liver damage. The protective effect of nitric oxide against apoptotic liver damage was partially reproduced by a membrane-permeable analog of cyclic GMP. On the other hand, treatment with the soluble guanylate cyclase inhibitor LY83583 overcame the protective effect of nitric oxide against apoptotic liver damage. These results suggest that nitric oxide may regulate programmed cell death in the mouse liver and that induction of genes, including inducible nitric oxide synthase, plays an important role in protecting the liver against LPS-induced apoptotic damage. This effect appears to be mediated, at least in part, via the soluble guanylate pathway.
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Apoptosis , Encefalopatía Hepática/tratamiento farmacológico , Óxido Nítrico/fisiología , Aminoquinolinas/farmacología , Animales , Fragmentación del ADN/efectos de los fármacos , Dactinomicina , GMP Dibutiril Cíclico/farmacología , Encefalopatía Hepática/sangre , Encefalopatía Hepática/inducido químicamente , Encefalopatía Hepática/patología , Hidroxilamina/farmacología , Lipopolisacáridos , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos ICR , Ratones Mutantes , Microscopía Confocal , Nitratos/sangre , Nitritos/sangre , Compuestos Nitrosos/farmacología , omega-N-Metilarginina/farmacologíaRESUMEN
We have reported that pretreatment of rat FRTL-5 thyroid cells with thyrotropin (TSH) markedly potentiates the mitogenic response to insulin-like growth factor-I (IGF-I). The present study was undertaken to determine whether the augmentation by cAMP of IGF-I-dependent tyrosine phosphorylation of known IGF-I receptor substrates plays an important role in the cAMP-dependent potentiation of DNA synthesis induced by IGF-I. Pretreatment with TSH or dibutyryl cAMP did not affect the IGF-I-dependent tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1). In contrast, cAMP pretreatment potentiated the tyrosine phosphorylation of IRS-2 induced by IGF-I, but did not affect the amount of IRS-2. We found that the IGF-I-dependent tyrosine phosphorylation of 66 kDa Shc (Src homology collagen) was markedly increased by cAMP pretreatment, and that this change was mainly due to an increase in the levels of 66 kDa Shc protein. Under these conditions, cAMP pretreatment significantly increased binding of Grb2 (growth-factor-receptor-bound protein 2) to Shc in response to IGF-I, and activation of MAP kinase (mitogen-activated protein kinase) induced by IGF-I was also enhanced by cAMP. The presence of PD98059, an inhibitor of MEK (MAP-kinase/Erk kinase), during treatment with IGF-I partially inhibited the cAMP-dependent augmentation of DNA synthesis in response to IGF-I. On the other hand, cAMP pretreatment increased binding of the phosphoinositide 3-kinase (PI 3-kinase) p85 subunit to IRS-2, which was reflected in PI 3-kinase activity. LY294002, a PI 3-kinase inhibitor, strongly depressed IGF-I-dependent DNA synthesis after pretreatment with and without TSH or dibutyryl cAMP. Our results suggest that the interaction between cAMP-dependent and IGF-I-dependent pathways leads to an augmentation of cell proliferation, which is mediated, at least in part, through the MAP kinase and PI 3-kinase signalling pathways. These effects are mediated by changes in tyrosine phosphorylation of IGF-I receptor substrates, including IRS-2 and Shc.
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Proteínas Adaptadoras Transductoras de Señales , Bucladesina/farmacología , AMP Cíclico/fisiología , Factor I del Crecimiento Similar a la Insulina/farmacología , Transducción de Señal/fisiología , Glándula Tiroides/fisiología , Tirotropina/farmacología , Animales , Línea Celular , Cromonas/farmacología , Inhibidores Enzimáticos/farmacología , Flavonoides/farmacología , Proteína Adaptadora GRB2 , Proteínas Sustrato del Receptor de Insulina , Péptidos y Proteínas de Señalización Intracelular , Cinética , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Morfolinas/farmacología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosfoproteínas/metabolismo , Fosforilación , Fosfotirosina/metabolismo , Proteínas/metabolismo , Ratas , Receptor de Insulina/fisiología , Transducción de Señal/efectos de los fármacos , Glándula Tiroides/efectos de los fármacos , Dominios Homologos srcRESUMEN
Washed human platelets were incubated under hypoxic and normoxic conditions to investigate the influence of oxygen deprivation on energy metabolism and aggregation. The maximum aggregation rate, oxygen consumption, lactate production, and adenine nucleotide content were measured. Hypoxic incubation decreased the oxygen burst and maximum aggregation induced by thrombin, and accelerated anaerobic glycolysis. ATP and ADP levels were preserved, but the hypoxanthine level increased in the incubation medium and the platelet AMP level and adenylate energy charge decreased compared with normoxic incubation. Thus, anaerobic glycolysis failed to compensate for impaired oxidative phosphorylation during hypoxic incubation, suggesting that oxidative energy is essential for full platelet function.
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Plaquetas/metabolismo , Oxígeno/metabolismo , Agregación Plaquetaria , Nucleótidos de Adenina/metabolismo , Adulto , Hipoxia de la Célula , Metabolismo Energético , Glucólisis , Humanos , Hipoxantina , Hipoxantinas/metabolismo , Técnicas In Vitro , Lactatos/metabolismo , Ácido Láctico , Masculino , Consumo de OxígenoRESUMEN
In FRTL-5 cells, we and others have shown that TSH and insulin-like growth factor-I (IGF-I) stimulate DNA synthesis synergistically. The present study was undertaken to determine whether interaction between TSH and IGF-I also affects protein synthesis in this cell line, and if so by what mechanism. Quiescent cells were treated with TSH and/or IGF-I and [3H]valine incorporation into the acid-insoluble fraction was measured as a parameter of protein synthesis. Similar to their effects on cell proliferation, TSH or IGF-I alone induced protein synthesis only slightly, but treatment with a combination of TSH and IGF-I (or insulin with about a 100-fold higher concentration than IGF-I) greatly increased protein synthesis. The presence of IGF-I potentiated a TSH-concentration-dependent increase in protein synthesis and in DNA synthesis. In addition, we observed this potentiation when the cells were treated with other cAMP-generating agents and cAMP analogues instead of TSH. We have shown that priming with TSH potentiated DNA synthesis induced by IGF-I, whereas pretreatment with IGF-I enhanced protein synthesis induced by TSH. This observation suggested that protein synthesis and DNA synthesis were potentiated through different mechanisms. From an analysis of cAMP production, it appears that the potentiation of protein synthesis may be explained by an IGF-I-dependent increase in cAMP production induced by TSH at least in part. On the other hand, IGF-I and TSH stimulated (alpha-aminoisobutyric acid (AIB) uptake synergistically, but RNA synthesis induced by IGF-I was depressed by TSH. From these results, we concluded that in FRTL-5 cells, IGF-I potentiated protein synthesis induced by TSH by means of complex mechanisms and the interaction between IGF-I and cAMP-dependent pathways may also have a physiological meaning in regulating protein anabolism.