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1.
Transfus Med ; 27(3): 213-217, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28230298

RESUMEN

BACKGROUND: Stored red blood cells (RBCs) undergo numerous changes that have been termed RBC storage lesion, which can be related to oxidative damage. Vitamin E is an important antioxidant, acting on cell lipids. Thus, this study aimed to investigate vitamin E activity on stored RBCs. METHODS: We prepared a vitamin E nanoemulsion that was added to RBC units and stored at 4 °C. Controls, without vitamin E, were kept under the same conditions. Reactive oxygen species (ROS) production was monitored for up to 35 days of storage. RBC elasticity was also evaluated using an optical tweezer system. RESULTS: Vitamin E-treated samples presented a significant decrease in ROS production. Additionally, the elastic constant for vitamin E-treated RBCs did not differ from the control. CONCLUSION: Vitamin E decreased the amount of ROS in stored RBCs. Because vitamin E acts on lipid oxidation, results suggest that protein oxidation should also be considered a key factor for erythrocyte elastic properties. Thus, further studies combining vitamin E with protein antioxidants deserve attention, aiming to better preserve overall stored RBC properties.


Asunto(s)
Conservación de la Sangre/métodos , Eritrocitos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Vitamina E/farmacología , Adulto , Emulsiones , Eritrocitos/citología , Humanos , Masculino , Oxidación-Reducción/efectos de los fármacos
2.
Genet Mol Res ; 13(3): 7636-48, 2014 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-25299077

RESUMEN

In Brazil, most cocoa bean production occurs in Southern Bahia. Witches' broom disease arrived in this area in 1989 and has since caused heavy losses in production. The disease is caused by the basidiomycete fungus Moniliophthora perniciosa, a hemibiotrophic fungus that produces the necrosis and ethylene-inducting protein (MpNEP2) during infection; this protein can activate cysteine proteases and induce programmed cell death. Cysteine proteases can be modulated by cystatin. In this study, we overexpressed TcCYS4, a cocoa cystatin, in tobacco plants and evaluated the effect on MpNEP2 in model plants. Tccys4 cDNA was cloned into the pCAMBIA 1390 vector and inserted into the tobacco plants via Agrobacterium tumefaciens. Transgene expression was analyzed by reverse transcription-quantitative PCR and Western blot analysis. Transcript and protein levels in Tcccys4:tobacco lines were 8.9- and 1.5-fold higher than in wild-type plants (wt). Tcccys4:tobacco lines showed no change in growth compared to wt plants. CO2 net assimilation (A) increased in Tcccys4:tobacco lines compared to wt plants. Only one line showed statistically significant stomatal conductance (gs) and transpiration rate (E) changes. MpNEP2 was infiltered into the foliar mesophyll of Tcccys4:tobacco lines and wt plants, and necrotic lesions were attenuated in lines highly expressing Tccys4. Our results suggest that cocoa cystatin TcCYS4 affects MpNEP2 activity related to the progression of programmed cell death in tobacco plants. This may occur through the action of cystatin to inhibit cysteine proteases activated by MpNEP2 in plant tissues. Further studies are necessary to examine cystatin in the Theobroma cacao-M. perniciosa pathosystem.


Asunto(s)
Basidiomycota/fisiología , Cacao/química , Cistatinas/farmacología , Proteínas Fúngicas/fisiología , Micosis/prevención & control , Nicotiana/efectos de los fármacos , Secuencia de Bases , Cartilla de ADN , Necrosis , Plantas Modificadas Genéticamente , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
3.
Scand J Immunol ; 78(1): 79-84, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23578109

RESUMEN

The understanding of the mechanisms involved in the immune response is of significant relevance to the control of tuberculosis (TB), especially in individuals living with patients with TB. To characterize the nitric oxide (NO) production and the Foxp3 marker expression in this population, peripheral blood mononuclear cells of intradomiciliary contacts of individuals with pulmonary tuberculosis with (CTb, susceptible) and without (STb, resistant) previous history of active infection were stimulated in vitro with Mycobacterium tuberculosis antigen (TbAg) and with the mitogen Concanavalin A for 24 and 48 h. The groups analysed did not present significant difference in the Foxp3 mRNA expression nor in the NO production. Negative correlation (P = 0.09) between NO and Foxp3 after a 48-h stimulation with TbAg was observed in the STb group. In this group, after a 24-h culture stimulated with TbAg (P = 0.03), this same correlation was observed. In comparison with the cytokines previously studied by our group (Cavalcanti et al., 2009), a positive correlation was observed between IL-10 and Foxp3 after a 48-h culture of cells from communicants susceptible to tuberculosis (STb) stimulated with TbAg (P = 0.04). Evaluating the entire population, a positive correlation was observed between the cytokine TNF-α and the Foxp3 marker in the cultures stimulated for 24 (P = 0.03) and 48 (P = 0.02) hours with TbAg. Therefore, considering the similarity in the exposure and the individual capacity of responding to the contact with M. tuberculosis, the present study contributes to the comprehension of the immune regulation in individuals living with patients with TB.


Asunto(s)
Factores de Transcripción Forkhead/fisiología , Leucocitos Mononucleares/metabolismo , Óxido Nítrico/biosíntesis , Tuberculosis Pulmonar/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Factores de Transcripción Forkhead/genética , Humanos , Interferón gamma/biosíntesis , Masculino , Persona de Mediana Edad , ARN Mensajero/análisis
4.
Scand J Immunol ; 76(2): 175-80, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22537157

RESUMEN

The influence of immune response on the treatment of American tegumentary leishmaniasis is pointed by several authors, and the existence of protective immunity in self-healed patients (SH) is also suggested. Thus, interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), interleukin (IL-) 10, IL-17, IL-22 and nitric oxide (NO) production was determined in PBMC culture supernatants from patients with active disease (AD) and after therapy, SH patients and healthy subjects, in response to the soluble antigen of Leishmania (Viannia) braziliensis. It was demonstrated that, during the active disease, there is a predominance of IFN-γ and TNF-α, indicating a proinflammatory phase of the response; IL-17 is also highlighted at this clinical state. Also, TNF-α was slightly increased in patients after therapy. NO secretion was noticed in SH individuals, while IL-17 appeared in low levels in these patients and seems to be regulated by NO. The presence of IL-10 was observed in all groups of patients. From this study, we can suggest that in the active disease and after clinical cure, with or without chemotherapy, specific cellular immunity takes part against Leishmania, but with some similarities between the clinical states. Thus, it indicates that the mediators herein described are necessary for the cure to occur.


Asunto(s)
Citocinas/inmunología , Leishmaniasis Cutánea/inmunología , Óxido Nítrico/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Células Cultivadas , Citocinas/biosíntesis , Femenino , Humanos , Leishmaniasis Cutánea/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Óxido Nítrico/biosíntesis , Adulto Joven
5.
Parasite Immunol ; 34(4): 236-9, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22394223

RESUMEN

American cutaneous leishmaniasis (ACL) has different clinical manifestations and these manifestations are dependent on the immunological status of the host. As CD4(+) and CD8(+) T cells and their mediators play a fundamental role in the host response to Leishmania and there is also a search for antigenic molecules to be used as future vaccines and tools for prognostic tests, this study characterized ACL patients' immune response after stimulation with soluble and insoluble fractions of L. (V.) braziliensis. We demonstrated a prevailing production of the Th2 cytokines, IL-4 and IL-10 and a specific production of IFN-γ and TNF-α in patients before treatment. There was also a predominance of CD4(+) T cells and a small percentage CD8(+) T cells. The insoluble antigenic fraction primarily stimulated CD4(+) T cells, while the soluble antigenic fraction showed a mixed profile, with CD4(+) T cells being the main responsible for Th2 cytokines and CD8(+) T cells for Th1 cytokines. Therefore, our results showed that a down-modulation of the Th1 type of response occurs in the initial phase of L. braziliensis disease, being the antigenic fractions capable of stimulating a specific immune response.


Asunto(s)
Antígenos de Protozoos/inmunología , Citocinas/metabolismo , Leishmania braziliensis/inmunología , Leishmania braziliensis/patogenicidad , Leishmaniasis Cutánea/inmunología , Células Th2/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos de Protozoos/química , Linfocitos T CD4-Positivos/inmunología , Femenino , Citometría de Flujo , Humanos , Interleucina-10/metabolismo , Interleucina-4/metabolismo , Leishmaniasis Cutánea/parasitología , Leishmaniasis Cutánea/fisiopatología , Masculino , Persona de Mediana Edad , Factores de Tiempo , Adulto Joven
6.
Electromyogr Clin Neurophysiol ; 50(7-8): 333-8, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21284371

RESUMEN

PURPOSE: [corrected] Compare the symmetry of the activity and masticatory muscles in individuals with TMD and asymptomatic. METHODS: The study included 50 women, while 31 had temporomandibular disorders (TMD) and 19 were asymptomatic (control group), aged between 19 and 40 years. The volunteers were subjected to clinical examination of the diagnostic criteria in research with TMD (RDC/TMD) with the aim of diagnosing volunteers with or without TMD, and evaluate the electromyographic activity of the right temporalis muscle (TR) and left (TL), right masseter (MR) and left (ML), in situations of rest, isometric contraction of the muscles of the jaw elevators. We obtained the rates of activity and asymmetry in each situation and for the collection and TMD control groups. RESULTS: For the index of activity for the rest there was significant difference (p = 0.0008) between the control group and the TMD group, with predominance of temporal muscle, was not observed difference between groups for the index of activity during the isometric contraction (p = 0.1069). For the index of asymmetry no difference between groups during rest, for the masseter muscles (p = 0.4182) and the temporal (p = 0.7614), and also during the isometry for both masseter muscles (p = 0.8691) and for time (p = 0.6643). CONCLUSIONS: The control group showed prevalence of TMD and temporal muscle during rest, which did not occur in the isometry, and no difference for the index of asymmetry between the groups for the masseter and temporal muscles.


Asunto(s)
Contracción Isométrica/fisiología , Músculo Masetero/fisiopatología , Relajación Muscular/fisiología , Músculo Temporal/fisiopatología , Trastornos de la Articulación Temporomandibular/fisiopatología , Adulto , Estudios de Casos y Controles , Estudios de Cohortes , Electromiografía , Femenino , Humanos , Músculo Masetero/patología , Masticación/fisiología , Músculo Temporal/patología , Trastornos de la Articulación Temporomandibular/patología , Adulto Joven
7.
Braz J Biol ; 80(1): 133-141, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31017241

RESUMEN

Beauveria bassiana is a promising fungus for the biological control of insect pests. The growing costs of conidia production have raised the need to ascertain the efficiency of some low cost substrates. The aim of this study was to analyze the potential use of different raw substrates without nutritional supplement for B. bassiana conidiogenesis. Growth and sporulation were evaluated using 30 g of substrate and 0.3 µL of a conidia suspension (1 x 106 conidia/mL). After 10 days of incubation (70 ± 10% humidity and temperature (T) = 29 ± 1 °C), rice (2.00 x 106 conidia/g substrate), algaroba (2.36 x 106 conidia/g), malt A (1.22 x 106 conidia/g) and malt B (1.75 x 106 conidia/g) showed the highest levels of conidia production. The resulting conidia showed insecticidal activity higher than 80% on coconut termites. These new raw substrates may represent viable alternatives for the production of entomopathogenic fungi for use in the biological control of various insect pests.


Asunto(s)
Beauveria , Hongos Mitospóricos , Humedad , Control Biológico de Vectores , Esporas Fúngicas
8.
Electromyogr Clin Neurophysiol ; 49(5): 245-54, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19694212

RESUMEN

PURPOSE: The aim of this study was to verify the effect of HVES on pain and electromyographic activity of the masticatory muscles in TMD patients, as well as assess the effect of this treatment on the severity of TMD. METHODS: Participated in this study 12 women with TMD that underwent electromyographic exam of the masticatory muscles, and responded to the FAI, RDC/TMD and VAS. RESULTS: After treatment, by the VAS a significant reduction in the intensity of pain it was verified; in the EMG that at rest and during isometric contraction of the mandibular depressor muscles there was a significant reduction in the RMS values; in voluntary contraction during maximal intercuspidation, a significant increase was observed in the values of RMS for the MD and ME muscles. CONCLUSION: HVES reduced the severity of TMD and the intensity of pain, and made the masticatory muscles approach their normal electromyographic pattern.


Asunto(s)
Terapia por Estimulación Eléctrica/métodos , Músculos Masticadores/fisiopatología , Manejo del Dolor , Trastornos de la Articulación Temporomandibular/complicaciones , Trastornos de la Articulación Temporomandibular/fisiopatología , Adulto , Electromiografía , Femenino , Humanos , Contracción Isométrica/fisiología , Dolor/etiología , Dolor/fisiopatología , Dimensión del Dolor , Resultado del Tratamiento , Adulto Joven
9.
Enzyme Res ; 2019: 8182425, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31275637

RESUMEN

Microbial lipases are prominent biocatalysts able to catalyze a wide variety of reactions in aqueous and nonaqueous media. In this work, filamentous fungi isolated from leaves decomposed in an aquatic environment were screened for lipase production with hydrolytic activity and esterification. Agar plates with Tween 20 and Rhodamine B were used for selection, while submerged cultures with olive oil were subsequently used to select 38 filamentous fungi. Trichoderma harzianum, Fusarium solani, Trichoderma harzianum F5, and Penicillium sp. F36 were grown in six different culture media. F. solani presented the highest lipase production (2.37 U/mL) with esterification activity of 0.07 U/mL using medium composed of (g.L-1) KH2PO4 1.00, MgSO4 H2O 1.123, and CuSO4 0.06. Supplementation of this culture medium with organic nitrogen sources increased lipase production by 461.3% using tryptone and by 419.4% using yeast extract. Among the vegetable oils from the Amazon region, degummed cotton oil induced lipase production up to 8.14 U/mL. The lipase produced by F. solani F61 has great potential to application in conventional processes and biodiesel production by transesterification of vegetable oils, as well as food industries in the production of fatty acid esters by hydrolysis and esterification.

10.
Int J Toxicol ; 27(3): 287-93, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18569170

RESUMEN

Sodium hydrosulfide and dimethylsulfide duplicate the effects of hydrogen sulfide in causing coma in Sprague-Dawley rats and are additive for lethality. Nitrite, pyruvate and dithiothreitol had no significant effect on coma or lethality but bicarbonate with and without glucose reduced duration of coma. This finding suggests an antidotal treatment.


Asunto(s)
Coma/inducido químicamente , Coma/tratamiento farmacológico , Modelos Animales de Enfermedad , Sulfuros/toxicidad , Animales , Masculino , Ratas , Ratas Sprague-Dawley
11.
Sci Rep ; 7(1): 11456, 2017 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-28904352

RESUMEN

Age-related complications such as neurodegenerative disorders are increasing and remain cureless. The possibility of altering the progression or the development of these multifactorial diseases through diet is an emerging and attractive approach with increasing experimental support. We examined the potential of known bioavailable phenolic sulfates, arising from colonic metabolism of berries, to influence hallmarks of neurodegenerative processes. In silico predictions and in vitro transport studies across blood-brain barrier (BBB) endothelial cells, at circulating concentrations, provided evidence for differential transport, likely related to chemical structure. Moreover, endothelial metabolism of these phenolic sulfates produced a plethora of novel chemical entities with further potential bioactivies. Pre-conditioning with phenolic sulfates improved cellular responses to oxidative, excitotoxicity and inflammatory injuries and this attenuation of neuroinflammation was achieved via modulation of NF-κB pathway. Our results support the hypothesis that these small molecules, derived from dietary (poly)phenols may cross the BBB, reach brain cells, modulate microglia-mediated inflammation and exert neuroprotective effects, with potential for alleviation of neurodegenerative diseases.


Asunto(s)
Barrera Hematoencefálica/metabolismo , Neuronas/efectos de los fármacos , Neuronas/metabolismo , Fármacos Neuroprotectores/farmacocinética , Polifenoles/farmacocinética , Animales , Disponibilidad Biológica , Transporte Biológico , Biomarcadores , Línea Celular , Cerebelo/citología , Cerebelo/efectos de los fármacos , Cerebelo/metabolismo , Cromatografía Liquida , Células Endoteliales de la Vena Umbilical Humana , Humanos , Espectrometría de Masas , Ratones , Microglía/efectos de los fármacos , Microglía/metabolismo , FN-kappa B/metabolismo , Fármacos Neuroprotectores/metabolismo , Permeabilidad , Polifenoles/metabolismo , Transporte de Proteínas
13.
Biochim Biophys Acta ; 465(1): 77-92, 1977 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-138443

RESUMEN

1. The rate of binding of [3H]ouabain to untreated membrane preparations of [Na+ +K+]-ATPase is a timperature--dependent process displaying a thermal transition close to 25degreesC. The apparent energies of activation which can be calculated above and below this transition are similar to, but not identical with, those previously reported for activation of the enzyme by cations. 2. Treatment of the enzyme preparation with detergents or lipolysis with phospholipase A eliminates the thermal transition resulting in linear Arrhenius plots. 3. The number of sites available for [3H]ouabain binding is not temperature dependent as the amount of [3H]ouabain bound at equillbrium is not changed between 10 and 37 degrees C. 4. Treatment of the enzyme with phospholipase A results in time-dependent changes in the number of binding sites for [3H]ouabain at equilibrium. 5. Treatment of the membrane enzyme preparations with detergents reveals additional [3H]ouabain binding sites which are extremely sensitive to lipolysis with phospholipase A. 6. There are a number of [3H]ouabain binding sites which remain resistant to lipolysis by phospholipase A in either untreated or detergent-treated membrane preparations. 7. It is suggested that [3H]ouabain binding sites exist in the membrane in at least two different environments, one of which is resistant the other sensitive to attack by phopholipase A.


Asunto(s)
Adenosina Trifosfatasas/metabolismo , Encéfalo/metabolismo , Membrana Celular/metabolismo , Movilización Lipídica , Ouabaína/metabolismo , Receptores de Droga/metabolismo , Animales , Bovinos , Activación Enzimática/efectos de los fármacos , Cinética , Ouabaína/farmacología , Fosfolipasas , Potasio/farmacología , Sodio/farmacología , Temperatura
14.
Braz. j. biol ; Braz. j. biol;80(1): 133-141, Feb. 2020. tab, graf
Artículo en Inglés | LILACS | ID: biblio-1089302

RESUMEN

Abstract Beauveria bassiana is a promising fungus for the biological control of insect pests. The growing costs of conidia production have raised the need to ascertain the efficiency of some low cost substrates. The aim of this study was to analyze the potential use of different raw substrates without nutritional supplement for B. bassiana conidiogenesis. Growth and sporulation were evaluated using 30 g of substrate and 0.3 μL of a conidia suspension (1 x 106 conidia/mL). After 10 days of incubation (70 ± 10% humidity and temperature (T) = 29 ± 1 °C), rice (2.00 x 106 conidia/g substrate), algaroba (2.36 x 106 conidia/g), malt A (1.22 x 106 conidia/g) and malt B (1.75 x 106 conidia/g) showed the highest levels of conidia production. The resulting conidia showed insecticidal activity higher than 80% on coconut termites. These new raw substrates may represent viable alternatives for the production of entomopathogenic fungi for use in the biological control of various insect pests.


Resumo Beauveria bassiana é um fungo promissor no controle biológico de insetos-praga. As crescentes despesas na produção de conídios levantam a necessidade de averiguar a eficiência de alguns substratos de baixo custo. O objetivo deste trabalho foi analisar o potencial de utilização de diferentes substratos brutos para a conidiogênese de B. bassiana. O crescimento e esporulação foram realizados utilizando 30 g do substrato e 0,3 µL da suspensão de conídios (1 x 106 conídios/mL). Após 10 dias de incubação (umidade 70 ± 10% e temperatura T = 29 ± 1° C), o arroz (2,00 x 106 conídios/g de substrato), algaroba (2,36 x 106 conídios/g), malte A (1,22 x 106 conídios/g) e B (1,75 x 106 conídios/g), apresentaram maior produção de conídios. Os conídios produzidos mostraram atividade inseticida sobre o cupim do coqueiro acima de 80% de mortalidade. Estes novos substratos brutos podem representar uma alternativa viável para produção de fungos entomopatogênicos para uso no controle biológico de vários insetos praga.


Asunto(s)
Hongos Mitospóricos , Beauveria , Esporas Fúngicas , Control Biológico de Vectores , Humedad
15.
FEBS Lett ; 176(2): 444-8, 1984 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-6489528

RESUMEN

Nitrobenzylthioniosine (NBMPR), a potent and specific inhibitor of nucleoside transport, is bound reversibly by high affinity sites on nucleoside transporter proteins of erythrocyte membranes and, upon photoactivation, NBMPR molecules become covalently bonded to the sites. This study showed that [3H]NBMPR molecules reversibly bound to intact S49 and L5178Y mouse lymphoma cells became covalently bound upon exposure to UV light. Electrophoretic analysis of plasma membrane fractions from the labelled cells showed that 3H was present in polypeptides which migrated as a major band with an apparent Mr of 45000-65000.


Asunto(s)
Marcadores de Afinidad/metabolismo , Proteínas Sanguíneas/metabolismo , Inosina/análogos & derivados , Linfoma/metabolismo , Proteínas de la Membrana/metabolismo , Tioinosina/análogos & derivados , Animales , Línea Celular , Electroforesis en Gel de Poliacrilamida , Membrana Eritrocítica/metabolismo , Leucemia L5178/metabolismo , Ratones , Proteínas de Transporte de Nucleósidos , Fotoquímica , Tioinosina/metabolismo , Rayos Ultravioleta
16.
J Appl Physiol (1985) ; 78(2): 433-40, 1995 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7759410

RESUMEN

The effects of sulfide on neonatal rat respiration were studied. Two in vitro experimental models were utilized: the isolated brain stem-spinal cord preparation and the medullary slice preparation containing respiratory rhythm-generating regions from neonatal rats. Plethysmographic measurements of the effects of sulfide on the breathing patterns of unanesthetized neonatal rats were also made to compare the sensitivities of neonatal and adult rats to sulfide toxicity. In vitro, sulfide acted at sites within the ventrolateral medulla to depress the frequency of respiratory rhythmic discharge by approximately 50-60%. However, the neuronal network underlying respiratory rhythmogenesis continued to function in the presence of concentrations of sulfide far beyond those deemed to be lethal in vivo. Intraperitoneal administration of sulfide caused a dose-dependent decrease in the frequency and amplitude of breathing of neonatal rats of all ages (0-19 days postnatal), although the sensitivity to sulfide increased with age. We hypothesize that the rapid suppression of breathing caused by sulfide is due to changes in neuronal excitability within respiratory rhythm-generating centers rather than, as previously hypothesized, to perturbations of cellular oxidative metabolism.


Asunto(s)
Neuronas/efectos de los fármacos , Mecánica Respiratoria/efectos de los fármacos , Sulfuros/farmacología , Envejecimiento/fisiología , Animales , Animales Recién Nacidos , Tronco Encefálico/efectos de los fármacos , Técnicas In Vitro , Bulbo Raquídeo/efectos de los fármacos , Pletismografía Total , Ratas , Ratas Sprague-Dawley , Médula Espinal/efectos de los fármacos
17.
Toxicol Sci ; 50(2): 287-93, 1999 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10478866

RESUMEN

Acute exposure to hydrogen sulfide (H2S) causes 4 dose-dependent responses: hyperpnea, unconsciousness or knockdown, apnea, and death. At present, scientific mechanisms for these effects are unknown, but inhibition of cytochrome oxidase in the central nervous system (CNS) by sulfide has been suggested. In this study, the premise of brain as target is examined by comparing peripheral with direct delivery of sulfide to brain. NaHS was administered to anesthetized Sprague-Dawley male rats, by femoral intravenous, or carotid intra-arterial injection. With apnea as the test, ED100 values of 0.6 and 3.0 mg kg(-1) were found for peripheral and direct delivery to brain, respectively. Peripheral delivery is 5 times as effective as direct delivery to the brain, and greater if the relative dilution factors are considered. Lidocaine, applied to the vagus, prevented apnea, so lung-brain transmission was essential. It was therefore concluded that the lung is the peripheral site of action. Hyperpnea increased in duration with dose. The carotid body, located distal to the arterial catheter, sensed the high doses of NaHS but did not trigger apnea. Intravenous infusion or intraperitoneal injection with NaHCO3 prevented hyperpnea, apnea, and death. The following conclusions are drawn: the carotid body is not implicated in NaHS-induced apnea, the lung and not brain harbors the primary site of action of H2S, and an afferent neural signal from the lung via the vagus induces the apnea. Finally, NaHCO3 appears to prevent toxicity from sulfide, and therefore H2S, by some unexplained mechanism. Practical emergency treatment for acute toxicity in the field may be possible.


Asunto(s)
Apnea/inducido químicamente , Encéfalo/efectos de los fármacos , Lidocaína/farmacología , Pulmón/efectos de los fármacos , Respiración/efectos de los fármacos , Sulfuros/toxicidad , Anestesia , Anestésicos Locales/farmacología , Animales , Bicarbonatos/farmacología , Arterias Carótidas , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Infusiones Intraarteriales , Infusiones Intravenosas , Inyecciones Intraperitoneales , Masculino , Ratas , Ratas Sprague-Dawley , Vena Safena
18.
Brain Res ; 344(1): 33-40, 1985 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-2412648

RESUMEN

Acid-acetone extracts of brain (from beef and guinea pig) and chlormadinone acetate (CMA) were compared with ouabain for their ability to inhibit the electrogenic Na+,K+-pump and the Na+,K+-ATPase of neuronal tissues. The membrane potential of neurones in the paravertebral sympathetic ganglion of the bullfrog was recorded in K+-free Ringer's solution by means of the sucrose gap technique. The potassium activated hyperpolarization (K+H), induced by the re-introduction of potassium, was used as an index of electrogenic Na+, K+-pumping. The K+H was blocked by 1 microM ouabain. Na+,K+-ATPase activity was measured in microsomal membrane preparations of frog and beef brain using a continuous spectrophotometric assay. Although ouabain consistently inhibited beef brain Na+,K+-ATPase (IC50 = 2.2 microM), acid-acetone extracts prepared from guinea pig and beef brain produced only partial inhibition. Neither of the extracts significantly reduced the K+H of the frog ganglion. CMA inhibited Na+,K+-ATPase prepared from bullfrog brain and spinal cord with slightly greater potency (IC50 = 4.5 microM) than did ouabain (IC50 = 10 microM). In contrast, electrogenic Na+,K+-pumping (i.e. the K+H) in the frog ganglion was not affected by this steroid. It is concluded that although both the extracts and CMA inhibited Na+,K+-ATPase, neither can be considered ouabain-like due to their failure to affect the electrogenic Na+,K+-pump in situ.


Asunto(s)
Química Encefálica , Acetato de Clormadinona/farmacología , Ganglios Simpáticos/efectos de los fármacos , Ouabaína/farmacología , ATPasa Intercambiadora de Sodio-Potasio/antagonistas & inhibidores , Animales , Ganglios Simpáticos/enzimología , Técnicas In Vitro , Rana catesbeiana
19.
Physiol Behav ; 60(3): 973-8, 1996 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8873278

RESUMEN

Changes in the protein content, maximal activity, and Km of phosphate-dependent glutaminase were measured in the lymphoid organs (thymus, spleen, and mesenteric lymph nodes) from just-weaned, mature (3 months), and aged rats (15 months). Also, [U-14C] glutamine transport and decarboxylation and the production of glutamate and aspartate from 2 and 20 mM glutamine were measured in incubated mesenteric lymph node lymphocytes. The ageing process induced a reduction in the protein content of the thymus and spleen, as well as the phosphate-dependent glutaminase activity in the thymus and isolated lymphocytes. The Km of phosphate-dependent glutaminase, however, was not affected by the process. Ageing reduced [U-14C] glutamine decarboxylation and increased glutamate and aspartate production in incubated lymphocytes. The results indicate that the ageing process does modify several aspects of glutamine metabolism in lymphocytes: reduces maximal glutaminase activity and [U-14C] glutamine decarboxylation and increases the Km for [U-14C] glutamine uptake and the production of glutamate and aspartate.


Asunto(s)
Envejecimiento/metabolismo , Ácido Glutámico/metabolismo , Ganglios Linfáticos/metabolismo , Linfocitos/metabolismo , Animales , Masculino , Ratas , Bazo/metabolismo , Timo/metabolismo
20.
Physiol Behav ; 53(4): 651-6, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8511168

RESUMEN

Key enzyme activities of glycolysis, pentosephosphate pathway, Krebs cycle, and glutaminolysis were measured in lymphocytes and macrophages of 3- and 15-month-old rats from the control, thioglycollate-injected, and Walker 256 tumor-implanted groups. The percentage of phagocytosis, phagocytic index, and production of H2O2 in macrophages and the rates of [2-14C]-thymidine and [5-3H]-uridine incorporation in cultured lymphocytes were also determined. The results indicate that the percentage of phagocytosis was not affected but the phagocytic index increased by twofold as a consequence of ageing, whereas the production of H2O2 reduced. The rates of both [2-14C]-thymidine and [5-3H]-uridine incorporation in lymphocytes from aged rats were lower as compared to those of mature animals in the three groups. Taken as a whole, the results of enzyme activities suggest that ageing may reduce the capacity for glucose utilization in lymphocytes and macrophages under the three conditions. Lymphocyte and macrophage glutamine metabolism was not markedly affected by ageing. Therefore, an impaired glucose metabolism during ageing may be one important mechanism for the alteration in lymphocyte proliferation and macrophage phagocytosis observed and also for the modification of the response to inflammatory and tumor challenges.


Asunto(s)
Envejecimiento/inmunología , Metabolismo Energético/fisiología , Linfocitos/fisiología , Macrófagos/fisiología , Animales , Carcinoma 256 de Walker/inmunología , Citrato (si)-Sintasa/fisiología , Ciclo del Ácido Cítrico/fisiología , Glucosafosfato Deshidrogenasa/metabolismo , Glutaminasa/fisiología , Glutamina/metabolismo , Glucólisis/fisiología , Hexoquinasa/fisiología , Peróxido de Hidrógeno/metabolismo , Activación de Linfocitos/inmunología , Masculino , Trasplante de Neoplasias , Vía de Pentosa Fosfato/fisiología , Fagocitosis/inmunología , Ratas
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