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1.
J Sports Sci ; 34(6): 576-83, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26691390

RESUMEN

Veteran football players above 40 years have rarely been subject to scientific investigations. This is worrisome because their number is considerable and their cardiovascular risk probably increased. Therefore, a cross-sectional study was conducted in 100 football players between 40 and 63 years of age. This included a medical history and physical examination, venous blood sampling, measurement of resting blood pressure, a resting electrocardiogram (ECG), an exhaustive cycle ergometry and a multistage field test. Also, measurements of heart rate and blood lactate concentration were carried out during one typical training session and one match. Participants trained 1.0 ± 0.6 sessions per week and played 27 ± 8 matches per season. Of them, 19% were smokers. Resting blood pressure was 138 ± 15/88 ± 8 mmHg. Hypertension prevalence (WHO definition) was 66%. Total cholesterol averaged 220 ± 41 mg . dl(-1), HDL 46 ± 13 mg . dl(-1) and LDL 134 ± 33 mg . dl(-1). The average 10-year risk for cardiovascular events (Framingham score) was 6%. Mean maximal power output on the cycle ergometer was 2.8 ± 0.6 W . kg(-1), mean VO2peak 40.0 ± 7.3 ml . min(-1) . kg(-1). Comparing training and competition, no significant differences in cardiovascular and metabolic load were found. In summary, their cardiovascular risk was similar to age-adjusted reference values. However, they showed slightly better ergometric performance. More frequent training stimuli might be necessary to reach more favourable risk factor profiles. Training and competition lead to similar cardiocirculatory and metabolic stress which is considerably high and might put players into danger who have pre-existing cardiac disease.


Asunto(s)
Enfermedades Cardiovasculares/epidemiología , Aptitud Física , Fútbol/fisiología , Adulto , Antropometría , Presión Sanguínea , Conducta Competitiva/fisiología , Estudios Transversales , Electrocardiografía , Prueba de Esfuerzo , Frecuencia Cardíaca , Humanos , Ácido Láctico/sangre , Lípidos/sangre , Masculino , Persona de Mediana Edad , Educación y Entrenamiento Físico , Prevalencia , Factores de Riesgo
2.
Pneumologie ; 70(2): 103-9, 2016 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-26640964

RESUMEN

Bronchial asthma is one of the most common chronic inflammatory diseases world-wide causing an enormous socio-economic burden especially in industrialized countries. Currently, asthma is increasingly considered to be a poly-symptomatic disease comprising a variety of different asthma phenotypes and endotypes. This heterogeneity of asthma explains why the standard treatment with corticosteroids and ß-agonists cannot achieve full symptom control in all cases, especially not during acute exacerbations. Therefore, current asthma research focuses on primary prevention of asthma as well as on novel approaches towards a phenotype- and endotype-specific asthma therapy.


Asunto(s)
Asma/fisiopatología , Asma/terapia , Biología Celular/tendencias , Neumología/tendencias , Investigación Biomédica Traslacional/tendencias , Animales , Humanos
3.
Clin Exp Allergy ; 45(9): 1447-58, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25772331

RESUMEN

BACKGROUND: Increased mucus production is a critical factor impairing lung function in patients suffering from bronchial asthma, the most common chronic inflammatory lung disease worldwide. OBJECTIVE: This study aimed at investigating whether goblet cell (GC) metaplasia and mucus production are differentially regulated in proximal and distal airways. METHODS: Female Balb/c mice were sensitized to ovalbumin (OVA) and challenged with an OVA-aerosol on two consecutive days for 1 week (acute) or 12 weeks (chronic). Real-time RT-PCR analysis was applied on microdissected airways. RESULTS: In acutely and chronically OVA-challenged mice, GC metaplasia and mucus production were observed in proximal but not in distal airways. In contrast, inflammation reflected by the infiltration of eosinophils and expression of the TH2-type cytokines IL-4 and IL-13 was increased in both proximal and distal airways. Abundance of IL-13Rα1 was lower in distal airways of healthy control mice. Under acute and chronic OVA-exposure, activation of IL-13Rα1-dependent signalling cascade, reflected by Spdef and Foxo3A transcription factors, was attenuated in distal compared to proximal airways. CONCLUSION AND CLINICAL RELEVANCE: These data indicate that distal airways might be less sensitive to IL-13-induced GC metaplasia and mucus production through lower expression of IL-13Rα1 and attenuated activation of downstream signalling. This might represent a protective strategy to prevent mucus plugging of distal airways and thus impaired ventilation of attached alveoli.


Asunto(s)
Asma/inmunología , Regulación de la Expresión Génica/inmunología , Células Caliciformes/inmunología , Interleucina-13/inmunología , Pulmón/inmunología , Transducción de Señal/inmunología , Animales , Asma/metabolismo , Asma/patología , Femenino , Proteína Forkhead Box O3 , Factores de Transcripción Forkhead/biosíntesis , Factores de Transcripción Forkhead/inmunología , Células Caliciformes/metabolismo , Células Caliciformes/patología , Interleucina-13/biosíntesis , Subunidad alfa1 del Receptor de Interleucina-13/biosíntesis , Subunidad alfa1 del Receptor de Interleucina-13/inmunología , Interleucina-4/biosíntesis , Interleucina-4/inmunología , Pulmón/metabolismo , Pulmón/patología , Metaplasia , Ratones , Ratones Endogámicos BALB C , Moco/inmunología , Moco/metabolismo , Proteínas Proto-Oncogénicas c-ets/biosíntesis , Proteínas Proto-Oncogénicas c-ets/inmunología , Células Th2/inmunología , Células Th2/metabolismo , Células Th2/patología
4.
Allergy ; 70(4): 366-73, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25557042

RESUMEN

BACKGROUND: Interleukin (IL) 37 has been described as a negative regulator of innate immunity, as it reduces the activation and cytokine production of different innate immune cells. Recently, results from the CLARA childhood asthma cohort suggested an implication of IL-37 for human asthma pathogenesis. This study aimed to investigate the effects of IL-37 on allergic airway inflammation in a mouse model of experimental asthma. METHODS: Peripheral blood mononuclear cells (PBMCs) of children were cultured for 48 h (anti-CD3/anti-CD28 stimulation or unstimulated), and IL-37 concentrations in supernatants were determined. Wild-type, IL-18Rα-deficient ((-/-) ), and SIGIRR(-/-) C57BL/6 mice were sensitized to ovalbumin (OVA) and challenged with OVA aerosol to induce acute experimental asthma, and IL-37 was applied intranasally prior to each OVA challenge. Airway hyper-responsiveness (AHR), airway inflammation, cytokine levels in broncho-alveolar lavage fluid, and mucus production were determined. RESULTS: IL-37 production of human PBMCs was significantly lower in allergic asthmatics vs healthy children. In wild-type mice, intranasal administration of IL-37 ablated allergic airway inflammation as well as cytokine production and subsequently diminished the hallmarks of experimental asthma including mucus hyperproduction and AHR. In contrast, local application of IL-37 produced none of these effects in mice lacking either IL18Rα or SIGIRR/IL-1R8. CONCLUSIONS: This study demonstrates that IL-37 is able to ablate a TH2 cell-directed allergic inflammatory response and the hallmarks of experimental asthma in mice, suggesting that IL-37 may be critical for asthma pathogenesis. Furthermore, these data suggest a mode of action of IL-37 that involves IL18Rα as well as the orphan receptor SIGIRR/IL-1R8.


Asunto(s)
Subunidad alfa del Receptor de Interleucina-18/metabolismo , Interleucina-1/metabolismo , Receptores de Interleucina-1/metabolismo , Hipersensibilidad Respiratoria/metabolismo , Adolescente , Animales , Asma/genética , Asma/inmunología , Asma/patología , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Niño , Preescolar , Citocinas/sangre , Citocinas/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Inflamación/genética , Inflamación/inmunología , Inflamación/patología , Interleucina-1/sangre , Subunidad alfa del Receptor de Interleucina-18/genética , Leucocitos Mononucleares/metabolismo , Ratones , Ratones Noqueados , Receptores de Interleucina-1/genética , Hipersensibilidad Respiratoria/genética , Hipersensibilidad Respiratoria/patología
5.
J Evol Biol ; 25(3): 584-90, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22239550

RESUMEN

Positive correlations between heterozygosity and fitness traits are frequently observed, and it has been hypothesized, but rarely tested experimentally, that parasites play a key role in mediating the heterozygosity-fitness association. We evaluated this hypothesis in a wild great tit (Parus major) population by testing the prediction that the heterozygosity-fitness association would appear in broods experimentally infested with a common ectoparasite, but not in parasite-free broods. We simultaneously assessed the effects of parental and offspring heterozygosity on nestling growth and found that body mass of nestlings close to independence, which is a strong predictor of post-fledging survival, increased significantly with nestling levels of heterozygosity in experimentally infested nests, but not in parasite-free nests. Heterozygosity level of the fathers also showed a significant positive correlation with offspring body mass under an experimental parasite load, whereas there was no correlation with the mothers' level of heterozygosity. Thus, our results indicate a key role for parasites as mediators of the heterozygosity-fitness correlations.


Asunto(s)
Tamaño Corporal/fisiología , Aptitud Genética/genética , Heterocigoto , Passeriformes/parasitología , Siphonaptera/fisiología , Animales , Femenino , Variación Genética , Genotipo , Funciones de Verosimilitud , Modelos Lineales , Masculino , Repeticiones de Microsatélite/genética , Carga de Parásitos , Passeriformes/genética , Passeriformes/crecimiento & desarrollo , Reacción en Cadena de la Polimerasa , Suiza
6.
Nat Med ; 11(6): 683-9, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15924146

RESUMEN

A promising approach to reduce the impact of influenza is the use of an attenuated, live virus as a vaccine. Using reverse genetics, we generated a mutant of strain A/WSN/33 with a modified cleavage site within its hemagglutinin, which depends on proteolytic activation by elastase. Unlike the wild-type, which requires trypsin, this mutant is strictly dependent on elastase. Both viruses grow equally well in cell culture. In contrast to the lethal wild-type virus, the mutant is entirely attenuated in mice. At a dose of 10(5) plaque-forming units, it induced complete protection against lethal challenge. This approach allows the conversion of any epidemic strain into a genetically homologous attenuated virus.


Asunto(s)
Glicoproteínas Hemaglutininas del Virus de la Influenza/metabolismo , Virus de la Influenza A/inmunología , Vacunas contra la Influenza , Animales , Anticuerpos Antivirales/biosíntesis , Línea Celular , Perros , Glicoproteínas Hemaglutininas del Virus de la Influenza/genética , Humanos , Virus de la Influenza A/genética , Virus de la Influenza A/fisiología , Gripe Humana/mortalidad , Gripe Humana/virología , Pulmón/virología , Ratones , Datos de Secuencia Molecular , Mutación , Elastasa Pancreática/metabolismo , Vacunas Atenuadas , Ensayo de Placa Viral , Replicación Viral
7.
Skin Pharmacol Physiol ; 24(4): 210-7, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21412035

RESUMEN

BACKGROUND: Due to its strong water binding potential, hyaluronic acid (HA) is a well-known active ingredient for cosmetic applications. However, based on its varying molecular size, skin penetration of HA may be limited. Recent studies have demonstrated that low-molecular-weight HA (LMW HA) may show a certain proinflammatory activity. We thus aimed to characterize an LMW-sized HA molecule that combines strong anti-aging abilities with efficient skin penetration but lacks potential proinflammatory effects. METHODS: Total RNA and total protein were isolated from reconstituted human epidermis following incubation with HAs of various molecular weights (20, 50, 130, 300, 800 and 1,500 kDa). Tumor necrosis factor-α expression was determined using quantitative PCR. Genomic and proteomic expression of various junctional proteins was determined using Affymetrix and common Western blotting techniques. RESULTS: LMWHA of approximately 50 kDa did not significantly alter tumor necrosis factor-α expression compared to 20-kDa HA, but revealed significantly higher skin penetration rates than larger sized HA associated with increased expression of genes and proteins known to be involved in tight junction formation and keratinocyte cohesion. CONCLUSION: LMW HA of approximately 50 kDa shows better penetration abilities than larger-sized HA. In addition, LMW HA influences the expression of various genes including those contributing to keratinocyte differentiation and formation of intercellular tight junction complexes without showing proinflammatory activity. These observations contribute to current knowledge on the effects of LMW HA on keratinocyte biology and cutaneous physiology.


Asunto(s)
Ácido Hialurónico/farmacología , Piel/efectos de los fármacos , Factor de Necrosis Tumoral alfa/biosíntesis , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Epidermis/efectos de los fármacos , Epidermis/metabolismo , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Ácido Hialurónico/química , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Peso Molecular , Piel/citología , Piel/metabolismo , Fenómenos Fisiológicos de la Piel/efectos de los fármacos , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia Arriba/efectos de los fármacos
8.
Nanoscale ; 11(28): 13458-13468, 2019 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-31287475

RESUMEN

The large number of nanomaterial-based applications emerging in the materials and life sciences and the foreseeable increasing use of these materials require methods that evaluate and characterize the toxic potential of these nanomaterials to keep safety risks to people and environment as low as possible. As nanomaterial toxicity is influenced by a variety of parameters like size, shape, chemical composition, and surface chemistry, high throughput screening (HTS) platforms are recommended for assessing cytotoxicity. Such platforms are not yet available for genotoxicity testing. Here, we present first results obtained for application-relevant nanomaterials using an automatable genotoxicity platform that relies on the quantification of the phosphorylated histone H2AX (γ-H2AX) for detecting DNA double strand breaks (DSBs) and the automated microscope system AKLIDES® for measuring integral fluorescence intensities at different excitation wavelengths. This platform is used to test the genotoxic potential of 30 nm-sized citrate-stabilized gold nanoparticles (Au-NPs) as well as micellar encapsulated iron oxide nanoparticles (FeOx-NPs) and different cadmium (Cd)-based semiconductor quantum dots (QDs), thereby also searching for positive and negative controls as reference materials. In addition, the influence of the QD shell composition on the genotoxic potential of these Cd-based QDs was studied, using CdSe cores as well as CdSe/CdS core/shell and CdSe/CdS/ZnS core/shell/shell QDs. Our results clearly revealed the genotoxicity of the Au-NPs and its absence in the FeOx-NPs. The genotoxicity of the Cd-QDs correlates with the shielding of their Cd-containing core, with the core/shell/shell architecture preventing genotoxicity risks. The fact that none of these nanomaterials showed cytotoxicity at the chosen particle concentrations in a conventional cell viability assay underlines the importance of genotoxicity studies to assess the hazardous potential of nanomaterials.


Asunto(s)
Cadmio/química , Histonas/metabolismo , Pruebas de Mutagenicidad/métodos , Nanoestructuras/toxicidad , Puntos Cuánticos/química , Cadmio/toxicidad , Supervivencia Celular , Roturas del ADN de Doble Cadena/efectos de los fármacos , Compuestos Férricos/química , Compuestos Férricos/toxicidad , Fluorometría , Oro/química , Oro/toxicidad , Nanopartículas del Metal/química , Nanopartículas del Metal/toxicidad , Pruebas de Mutagenicidad/instrumentación , Nanoestructuras/química , Tamaño de la Partícula , Fosforilación/efectos de los fármacos , Puntos Cuánticos/toxicidad
9.
Transplant Proc ; 40(9): 3229-36, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19010241

RESUMEN

Humoral rejection is an important cause of early and late graft loss. The late variant is difficult to diagnose and treat. There is a close correlation between sclerosing nephropathy and anti-HLA antibodies. We analyzed 113 renal allograft recipients between August 2004 and April 2007. Acute humoral rejection was defined as acute graft dysfunction in presence of donor-specific antibodies (DSA) detected by flow panel reactive antibodies (PRA) and/or C4d positive pericapilary tubules (PTC) detected histopathologically by immunofluorescent or immunoperoxidase at less than 3 months postransplantation. Late humoral rejection was defined as dysfunction occurring after 3 months postransplantation with histopathologic glomerulopathy or vasculopathy and positive C4d PTC. We included all patients who were diagnosed with early or late graft dysfunction and underwent biopsy, all of which were examined for C4d. Four patients had acute humoral rejection treated with IVIG or plasmapheresis. The patient and graft survivals were 100% and serum creatinine averaged 1.7 mg/dL. Three recipients experienced late humoral rejection at 3 to 10 years posttransplantation All received high-dose IVIG; one also was treated with thymoglobulin. Immunosuppression was switched to tacrolimus, mycophenolate mofetil, and steroids. Only one patient recovered renal function; the others returned to dialysis. Among seven patients only one had an actual PRA (>20%) and three showed 10% to 20%. However, six had a positive historical PRA of 10% to 50%. In conclusion, Recognition of acute humoral rejection has contributed to graft rescue by controlling alloantibody production through new specific immunosuppressive therapies in contrast with the clinical response to acute therapy, treatment of a chronic entity has shown poor outcomes, probably because antibody mediated chronic graft damage is already present when the late diagnosis is established by biopsy.


Asunto(s)
Formación de Anticuerpos , Rechazo de Injerto/inmunología , Rechazo de Injerto/patología , Trasplante de Riñón/inmunología , Trasplante de Riñón/patología , Anticuerpos Monoclonales/inmunología , Anticuerpos Monoclonales/uso terapéutico , Antígenos CD/inmunología , Antígenos CD20/inmunología , Suero Antilinfocítico , Biopsia , Linfocitos T CD4-Positivos/inmunología , Creatinina/sangre , Estudios de Seguimiento , Rechazo de Injerto/tratamiento farmacológico , Humanos , Inmunoglobulinas Intravenosas/uso terapéutico , Inmunosupresores/uso terapéutico , Plasmaféresis , Factores de Tiempo , Trasplante Homólogo/inmunología , Trasplante Homólogo/patología
10.
Diabetes Care ; 10(6): 683-6, 1987.
Artículo en Inglés | MEDLINE | ID: mdl-3428047

RESUMEN

The hypoglycemic effect of 2.5 mg glipizide and the potentiation of this effect by ethanol were studied in 10 normal-weight nondiabetic subjects. The reductions in blood glucose concentrations were similar in time of onset and extent (2 mM) whether glipizide was taken alone or in combination with ethanol. However, the return of blood glucose toward fasting level was delayed by ethanol. Beta-Cell secretory activity, evaluated from the concentrations of insulin and C-peptide, was unchanged by ethanol. The serum glipizide concentrations were reproducible within subjects, whereas there was a considerable interindividual variation. This heterogeneity in the rise in glipizide concentration was strongly correlated with blood glucose fall and insulin secretion. Thus, ethanol can prolong but does not augment the hypoglycemia induced by glipizide. The heterogeneity in glipizide concentration seems to be caused by an interindividual variation in kinetics.


Asunto(s)
Glucemia/metabolismo , Etanol/farmacología , Glipizida/farmacología , Compuestos de Sulfonilurea/farmacología , Adulto , Interacciones Farmacológicas , Femenino , Humanos , Cinética , Masculino , Factores de Tiempo
11.
Arch Neurol ; 43(7): 698-701, 1986 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-3729749

RESUMEN

Brain-stem auditory evoked responses were measured during sleep in four infants with congenital central alveolar hypoventilation syndrome (Ondine's syndrome) and four controls matched for age and sex. Delays in peak latencies p III and interpeak latencies p I-III were consistently seen in these patients but not in the control children. These abnormalities were reproducible and suggested disruption in the normal auditory pathways at the level of the mid to upper brain stem through which fibers pass close to the area of respiratory control. These abnormalities, both electrophysiologic and metabolic, imply a functional disturbance of brain-stem control of ventilation during sleep in infants and children suffering from Ondine's syndrome.


Asunto(s)
Audiometría de Respuesta Evocada , Tronco Encefálico/fisiopatología , Síndromes de la Apnea del Sueño/fisiopatología , Encéfalo/diagnóstico por imagen , Computadores , Electrocardiografía , Electroencefalografía , Humanos , Lactante , Masculino , Enfermedad Cardiopulmonar/diagnóstico , Sueño , Síndromes de la Apnea del Sueño/complicaciones , Volumen de Ventilación Pulmonar , Tomografía Computarizada por Rayos X , Vigilia
12.
Am J Cardiol ; 87(6): 813-5, A9, 2001 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-11249915

RESUMEN

Aortic dissection was found in a woman, her 2 sons, and 1 of her 3 daughters, and the 3 affected children and a granddaughter had patent ductus arteriosus. The pattern of inheritance of this unique syndrome probably is an autosomal dominant one.


Asunto(s)
Aneurisma de la Aorta/genética , Disección Aórtica/genética , Conducto Arterioso Permeable/genética , Adulto , Anciano , Disección Aórtica/complicaciones , Aneurisma de la Aorta/complicaciones , Conducto Arterioso Permeable/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Linaje
13.
Sleep ; 8(4): 342-6, 1985 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3880174

RESUMEN

Impedance respiratory monitoring is not capable of detecting obstructive apneas. We compared a microphone breath sound detector, coupled to the chest wall, with a standard impedance device in 10 sleeping infants and children in order to determine the ability of the breath sound detector to detect normal respirations and central and obstructive apneas. Airflow was used as a standard for all measurements. No difference was found between the breath sound detector and impedance device techniques in the detection rate of either normal respirations or central apneic intervals. There was no statistically significant difference between breath sounds and airflow in the ability of either technique to detect obstructive apnea. The use of a breath sound detector avoids unnecessary stimulation of a sleeping child, whose monitoring would otherwise require that two or three airflow sensing devices be taped on the face. Breath sound monitoring may represent an alternative to impedance and airflow techniques for evaluation of apnea in closely observed infants and children.


Asunto(s)
Cardiografía de Impedancia , Pletismografía de Impedancia , Ventilación Pulmonar , Ruidos Respiratorios , Síndromes de la Apnea del Sueño/diagnóstico , Tráquea/fisiopatología , Adolescente , Niño , Preescolar , Humanos , Lactante , Síndromes de la Apnea del Sueño/fisiopatología
14.
Chest ; 100(4): 999-1002, 1991 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1914620

RESUMEN

Clinicians who auscultate the chest of normal children note that the frequency content of their breath sounds appears to vary with age. Because these changes have not been systematically documented before, we recorded and analyzed inspiratory breath sounds in 35 children (0 to 13 years) and five adults (34 to 43 years). Our objective was to determine if the frequency content of normal breath sounds differed with age. Using a Fast Fourier Transform program, we calculated an average amplitude frequency spectrum from the inspiratory portion of the breath sounds of each subject (n = 10 breaths), and we compared the shape of the AFS and the values of selected frequency parameters. We found that the shape of the AFS of the youngest children differed most from the AFS of adults. Three of four selected frequency parameters (F25, F50, F95) differed significantly between children and adults (p less than 0.05), and one parameter (F75) did not (p = 0.11). The F25, F50, and F75 parameters of children (but not F95) were correlated (p less than 0.001) with increasing height and age. These results suggest that differences in the frequency content of the normal breath sounds of children and adults contribute to the differences that clinicians detect during clinical auscultation.


Asunto(s)
Ruidos Respiratorios/fisiología , Adulto , Envejecimiento/fisiología , Conversión Analogo-Digital , Auscultación , Niño , Estudios Transversales , Femenino , Análisis de Fourier , Humanos , Masculino , Valores de Referencia , Espectrografía del Sonido
15.
J Appl Physiol (1985) ; 62(5): 2066-74, 1987 May.
Artículo en Inglés | MEDLINE | ID: mdl-2954941

RESUMEN

The influence of OKY 1581, a thromboxane synthase inhibitor, on airway responses to arachidonic acid and endoperoxide, [prostaglandin (PG) H2], were investigated in anesthetized, paralyzed, mechanically ventilated cats. Intravenous injections of arachidonic acid and PGH2 caused dose-related increases in transpulmonary pressure and lung resistance and decreases in dynamic and static compliance. OKY 1581 significantly decreased airway responses to arachidonic acid but not to PGH2. Sodium meclofenamate, a cyclooxygenase inhibitor, abolished airway responses to arachidonic acid but had no effect on airway responses to PGH2. OKY 1581 or meclofenamate has no effect on airway responses to PGF2 alpha, PGD2, or U 46619, a thromboxane mimic. In microsomal fractions from the lung, OKY 1581 inhibited thromboxane formation without decreasing prostacyclin synthesis or cyclooxygenase activity. These studies show that OKY 1581 is a selective thromboxane synthesis inhibitor in the cat lung and suggest that a substantial part of the bronchoconstrictor response to arachidonic acid is due to thromboxane A2 formation. Moreover, the present data suggest that airway responses to endogenously released and exogenous PGH2 are mediated differently and that a significant part of the response to exogenous PGH2 may be due to activation of an endoperoxide/thromboxane receptor, since responses to PGH2 are blocked by the thromboxane receptor antagonist SQ 29548.


Asunto(s)
Acrilatos/farmacología , Ácidos Araquidónicos/farmacología , Bronquios/efectos de los fármacos , Metacrilatos/farmacología , Endoperóxidos de Prostaglandinas Sintéticos/farmacología , Endoperóxidos de Prostaglandina/farmacología , Prostaglandinas H/farmacología , Resistencia de las Vías Respiratorias/efectos de los fármacos , Animales , Ácido Araquidónico , Ácidos Araquidónicos/metabolismo , Bronquios/fisiología , Gatos , Dinoprost , Prostaglandina D2 , Prostaglandina H2 , Prostaglandinas D/farmacología , Prostaglandinas F/farmacología , Receptores de Prostaglandina/efectos de los fármacos , Receptores de Prostaglandina/fisiología , Receptores de Tromboxanos , Tromboxano-A Sintasa/antagonistas & inhibidores
16.
Artículo en Inglés | MEDLINE | ID: mdl-14580365

RESUMEN

We examined the direct epithelial effects of the major product of arachidonic acid metabolism in the kidney, prostaglandin E(2) (PGE(2)), on ion transport and signal transduction in the hormone-sensitive Madin-Darby canine kidney (MDCK) C7 subclone as a model of renal collecting duct principal cells. MDCK C7 cells were grown on microporous permeable filter supports and mounted in Ussing-type chambers. Reverse transcriptase (RT)-PCR and sequencing were used to determine E-prostanoid (EP) receptor expression. Basolateral and, about 14-fold less potent, apical addition of PGE(2) increased short-circuit current (I(sc)) in a concentration-dependent manner. This ion transport was biphasic with a rapid peak not detectable under chloride-free conditions. The remaining, stably elevated current was unaffected by furosemide, hydrochlorothiazide, ethylisopropanol amiloride, and 5-nitro-2-(3-phenyl-propyl-amino)benzoic acid (NPPB). In contrast, apical amiloride (10 microM) significantly decreased I(sc), indicating sodium reabsorption. The effect of PGE(2) was attenuated in the presence of vasopressin. Agonists acting by cAMP elevation like dibutyryl-cAMP and theophylline also induced an amiloride-sensitive ion transport with similar kinetics as PGE(2). Moreover, PGE(2) rapidly increased intracellular cAMP levels. RT-PCR demonstrated mRNA expression of the epithelial sodium channel (ENaC), and of the EP2 receptor in MDCK C7 cells. Accordingly, EP2 receptor agonist butaprost mimicked PGE(2) epithelial action. In conclusion, PGE(2) induces amiloride-sensitive sodium reabsorption in MDCK C7 monolayers. This ion transport is most likely mediated by EP2 receptor activation leading to increased intracellular cAMP levels. Therefore, PGE(2) might also contribute to Na(+) reabsorption in the mammalian collecting duct.


Asunto(s)
Alprostadil/análogos & derivados , Dinoprostona/metabolismo , Células Epiteliales/metabolismo , Túbulos Renales Colectores/metabolismo , Sodio/metabolismo , Alprostadil/farmacología , Animales , Bucladesina/farmacología , Línea Celular , AMP Cíclico/metabolismo , Perros , Células Epiteliales/citología , Células Epiteliales/efectos de los fármacos , Canales Epiteliales de Sodio , Túbulos Renales Colectores/citología , Técnicas de Placa-Clamp , Prostaglandinas E Sintéticas/farmacología , Receptores de Prostaglandina E/metabolismo , Sistemas de Mensajero Secundario/fisiología , Canales de Sodio/genética , Canales de Sodio/metabolismo , Teofilina/farmacología
17.
Life Sci ; 55(14): PL251-6, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-8090050

RESUMEN

Responses to synthetic human adrenomedullin, a novel hypotensive peptide localized in several organ systems, including the lung, and the carboxy terminal 15-52 amino acid fragment of adrenomedullin (ADM15-52) were investigated in the pulmonary vascular bed of the intact-chest cat. Under constant flow conditions when baseline tone in the pulmonary vascular bed was raised to a high steady level, injections of adrenomedullin and ADM15-52 into the perfused lobar artery in doses of 0.1-1 nmol, caused significant dose-related decreases in lobar arterial pressure. Since left atrial pressure was unchanged, the decreases in lobar arterial pressure reflect decreases in pulmonary lobar vascular resistance. Adrenomedullin and ADM15-52 exhibited similar vasodilator activity and were approximately 3-fold more potent than bradykinin in the pulmonary vascular bed of the cat. Pulmonary vasodilator responses to adrenomedullin and ADM15-52 were rapid in onset and lasted for 150-200 sec, depending on the dose of the peptide injected. The present results demonstrate that synthetic human adrenomedullin and ADM15-52 possess potent, short-lasting vasodilator activity in the pulmonary vascular bed of the cat and suggest that amino acids 15-52 in the peptide are important for the expression of vasodilator activity in the pulmonary vascular bed of the cat.


Asunto(s)
Antihipertensivos/farmacología , Péptidos/farmacología , Circulación Pulmonar/efectos de los fármacos , Vasodilatadores/farmacología , Adrenomedulina , Animales , Antihipertensivos/farmacocinética , Presión Sanguínea/efectos de los fármacos , Gatos , Femenino , Masculino , Péptidos/farmacocinética
20.
Phys Rev B Condens Matter ; 48(10): 7739-7741, 1993 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-10006956
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