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BACKGROUND: Despite the current debate about the effects of high intensity interval training (HIIT), HIIT elicits big morpho-physiological benefit on Metabolic Syndrome (MetS) treatment. However, no review or meta-analysis has compared the effects of HIIT to non-exercising controls in MetS variables. The aim of this study was to determine through a systematic review, the effectiveness of HIIT on MetS clinical variables in adults. METHODS: Studies had to be randomised controlled trials, lasting at least 3 weeks, and compare the effects of HIIT on at least one of the MetS clinical variables [fasting blood glucose (BG), high-density lipoprotein (HDL-C) triglyceride (TG), systolic (SBP) or diastolic blood pressure (DBP) and waist circumference (WC)] compared to a control group. The methodological quality of the studies selected was evaluated using the PEDro scale. RESULTS: Ten articles fulfilled the selection criteria, with a mean quality score on the PEDro scale of 6.7. Compared with controls, HIIT groups showed significant and relevant reductions in BG (- 0.11 mmol/L), SBP (- 4.44 mmHg), DBP (- 3.60 mmHg), and WC (- 2.26 cm). Otherwise, a slight increase was observed in HDL-C (+ 0.02 mmol/L). HIIT did not produce any significant changes in TG (- 1.29 mmol/L). CONCLUSIONS: HIIT improves certain clinical aspects in people with MetS (BG, SBP, DBP and WC) compared to people with MetS who do not perform physical exercise. Plausible physiological changes of HIIT interventions might be related with large skeletal muscle mass implication, improvements in the vasomotor control, better baroreflex control, reduction of the total peripheral resistance, increases in excess post-exercise oxygen consumption, and changes in appetite and satiety mechanisms.
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Biomarcadores/análise , Treinamento Intervalado de Alta Intensidade , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/terapia , Composição Corporal , Reabilitação Cardíaca , Estudos de Casos e Controles , Humanos , Síndrome Metabólica/metabolismo , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Since Toll-like receptor 4 (TLR4) mediates brain damage after stroke, development of TLR4 antagonists is a promising therapeutic strategy for this disease. Our aim was to generate TLR4-blocking DNA aptamers to be used for stroke treatment. From a random oligonucleotide pool, we identified two aptamers (ApTLR#1R, ApTLR#4F) with high affinity for human TLR4 by systematic evolution of ligands by exponential enrichment (SELEX). Optimized truncated forms (ApTLR#1RT, ApTLR#4FT) were obtained. Our data demonstrate specific binding of both aptamers to human TLR4 as well as a TLR4 antagonistic effect. ApTLR#4F and ApTLR#4FT showed a long-lasting protective effect against brain injury induced by middle cerebral artery occlusion (MCAO), an effect that was absent in TLR4-deficient mice. Similar effects were obtained in other MCAO models, including in rat. Additionally, efficacy of ApTLR#4FT in a model of brain ischemia-reperfusion in rat supports the use of this aptamer in patients undergoing artery recanalization induced by pharmacological or mechanical interventions. The absence of major toxicology aspects and the good safety profile of the aptamers further encourage their future clinical positioning for stroke therapy and possibly other diseases in which TLR4 plays a deleterious role.
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Aptâmeros de Nucleotídeos/administração & dosagem , Infarto da Artéria Cerebral Média/tratamento farmacológico , Acidente Vascular Cerebral/prevenção & controle , Receptor 4 Toll-Like/metabolismo , Animais , Aptâmeros de Nucleotídeos/farmacologia , Modelos Animais de Doenças , Humanos , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/etiologia , Camundongos , Ratos , Técnica de Seleção de Aptâmeros , Transdução de Sinais , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/metabolismoRESUMO
BACKGROUND: The beneficial effects in lipid profiles after obesity surgery might be associated with the decrease in cardiovascular risk. However, direct comparison between different surgical techniques has not been extensively performed. METHODS: In the present study we compare 20 obese women submitted to laparoscopic Roux en Y gastric bypass (RYGB) with 20 women submitted to sleeve gastrectomy (SG). Twenty control women matched for age and baseline cardiovascular risk were also included. Both patients and controls were followed up for 1 year after surgery or conventional treatment with diet and exercise, respectively. Lipid profiles were measured at baseline, 6 and 12 months later. Carotid intima-media thickness was measured by ultrasonography at baseline and at the end of the study. RESULTS: Women submitted to bariatric surgery showed a decrease in total cholesterol, triglycerides, oxidized-LDL and ApoB, and an increase in HDL and ApoA concentrations that occurred regardless of the surgical procedure. LDL concentrations, however, decreased only after RYGB whereas Lp(a) showed no changes. We did not observe any correlation between the changes in serum lipid concentrations and those in carotid intima-media thickness. CONCLUSIONS: Sleeve gastrectomy and gastric bypass induce a similar beneficial effect on serum lipids in women with high cardiovascular risk 1 year after surgery.
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Gastrectomia/métodos , Derivação Gástrica , Gastroplastia/métodos , Obesidade Mórbida/sangue , Obesidade Mórbida/cirurgia , Adulto , Apolipoproteínas A/sangue , Apolipoproteínas B/sangue , Restrição Calórica , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/prevenção & controle , Artérias Carótidas/diagnóstico por imagem , Espessura Intima-Media Carotídea , Estudos de Casos e Controles , Exercício Físico , Feminino , Seguimentos , Humanos , Lipoproteínas HDL/sangue , Lipoproteínas LDL/sangue , Pessoa de Meia-Idade , Obesidade Mórbida/dietoterapia , Obesidade Mórbida/patologia , Risco , Triglicerídeos/sangue , UltrassonografiaRESUMO
INTRODUCTION: Transient headache and neurological deficits with cerebrospinal fluid lymphocytosis (HaNDL) is characterised by migraine-like headache episodes accompanied by neurological deficits consisting of motor, sensory, or aphasic symptoms. Electroencephalogram (EEG) and single photon emission computed tomography (SPECT) may show focal abnormalities that correspond to the neurological deficits. We aim to evaluate the correlation between focal deficit topography and EEG or SPECT abnormalities in 5 new cases. PATIENTS: We retrospectively reviewed patients attended in a tertiary hospital (January 2010-May 2014) and identified 5 patients (3 men, 2 women) with a mean age of 30.6 ± 7.7 (21-39) years. They presented 3.4 ± 2.6 episodes of headache (range, 2-8) of moderate to severe intensity and transient neurological deficits over a maximum of 5 weeks. Pleocytosis was detected in CSF in all cases (70 to 312 cells/mm3, 96.5-100% lymphocytes) with negative results from aetiological studies. RESULTS: At least one EEG was performed in 4 patients and SPECT in 3 patients. Patient 1: 8 episodes; 4 left hemisphere, 3 right hemisphere, and 1 brainstem; 2 EEGs showing left temporal and bilateral temporal slowing; normal SPECT. Patient 2: 2 episodes, left hemisphere and right hemisphere; SPECT showed decreased left temporal blood flow. Patient 3: 3 left hemisphere deficits; EEG with bilateral frontal and temporal slowing. Patient 4: 2 episodes with right parieto-occipital topography and right frontal slowing in EEG. Patient 5: 2 episodes, right hemisphere and left hemisphere, EEG with right temporal slowing; normal SPECT. CONCLUSION: The neurological deficits accompanying headache in HaNDL demonstrate marked clinical heterogeneity. SPECT abnormalities and most of all EEG abnormalities were not uncommon in our series and they did not always correlate to the topography of focal déficits.
Assuntos
Eletroencefalografia/métodos , Linfocitose/complicações , Transtornos de Enxaqueca/diagnóstico , Doenças do Sistema Nervoso/diagnóstico , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Adulto , Feminino , Humanos , Leucocitose/líquido cefalorraquidiano , Linfocitose/líquido cefalorraquidiano , Masculino , Transtornos de Enxaqueca/líquido cefalorraquidiano , Transtornos de Enxaqueca/diagnóstico por imagem , Transtornos de Enxaqueca/etiologia , Estudos Retrospectivos , Espanha , SíndromeRESUMO
Poor oxygenation (hypoxia) influences important physiological and pathological situations, including development, ischemia, stroke and cancer. Hypoxia induces protein synthesis inhibition that is primarily regulated at the level of initiation step. This regulation generally takes place at two stages, the phosphorylation of the subunit α of the eukaryotic initiation factor (eIF) 2 and the inhibition of the eIF4F complex availability by dephosphorylation of the inhibitory protein 4E-BP1 (eukaryotic initiation factor 4E-binding protein 1). The contribution of each of them is mainly dependent of the extent of the oxygen deprivation. We have evaluated the regulation of hypoxia-induced translation inhibition in nerve growth factor (NGF)-differentiated PC12 cells subjected to a low oxygen concentration (0.1%) at several times. Our findings indicate that protein synthesis inhibition occurs primarily by the disruption of eIF4F complex through 4E-BP1 dephosphorylation, which is produced by the inhibition of the mammalian target of rapamycin (mTOR) activity via the activation of REDD1 (regulated in development and DNA damage 1) protein in a hypoxia-inducible factor 1 (HIF1)-dependent manner, as well as the translocation of eIF4E to the nucleus. In addition, this mechanism is reinforced by the increase in 4E-BP1 levels, mainly at prolonged times of hypoxia.
Assuntos
Hipóxia Celular , Fator de Iniciação 4F em Eucariotos/metabolismo , Fator de Crescimento Neural/farmacologia , Neurônios/metabolismo , Biossíntese de Proteínas , Trifosfato de Adenosina/metabolismo , Animais , Proteínas de Transporte/metabolismo , Diferenciação Celular , Fator de Iniciação 4F em Eucariotos/genética , Peptídeos e Proteínas de Sinalização Intracelular , Neurônios/citologia , Células PC12 , Fosfoproteínas/metabolismo , RatosRESUMO
The effects of undernutrition during pregnancy on prenatal and postnatal development of the offspring were evaluated in sows with obesity/leptin resistance. Females were fed, from day 35 of pregnancy onwards, a diet fulfilling either 100% (group control, n=10) or 50% of the nutritional requirements (group underfed, n=10). In the control group, maternal body weight increased during pregnancy (P<0.05) while it decreased or remained steady in the underfed group. At days 75 and 100 of gestation, plasma triglycerides were lower but urea levels were higher in restricted than in control sows (P<0.05 for both). Assessment of the offspring indicated that the trunk diameter was always smaller in the restricted group (P<0.01 at day 50, P<0.005 at days 75 and 100 and P<0.0001 at birth) while head measurements were similar through pregnancy, although smaller in the restricted than in the control group at birth (P<0.05). Newborns from restricted sows were also lighter than offspring from control females (P<0.01) and had higher incidence of growth retardation (P<0.01). Afterwards, during lactation, early postnatal growth in restricted piglets was modulated by gender. At weaning, males from restricted sows were still lighter than their control counterparts (P<0.05), while females from control and underfed sows were similar. Thus, the current study indicates a gender-related differential effect in the growth patterns of the piglets, with females from restricted sows evidencing catch-up growth to neutralise prenatal retardation and reaching similar development than control counterparts.
Assuntos
Resistência a Medicamentos , Retardo do Crescimento Fetal/reabilitação , Obesidade/complicações , Suínos/crescimento & desenvolvimento , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Peso Corporal , Restrição Calórica/efeitos adversos , Resistência a Medicamentos/fisiologia , Feminino , Retardo do Crescimento Fetal/etiologia , Retardo do Crescimento Fetal/fisiopatologia , Retardo do Crescimento Fetal/veterinária , Alimentos , Leptina/metabolismo , Leptina/farmacologia , Masculino , Obesidade/metabolismo , Obesidade/veterinária , Gravidez , Complicações na Gravidez/etiologia , Complicações na Gravidez/metabolismo , Complicações na Gravidez/veterinária , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/reabilitação , Caracteres SexuaisRESUMO
Iberian pigs and its crosses are produced to obtain high-quality meat products. The objective of this work was to evaluate a wide panel of DNA markers, selected by biological and functional criteria, for association with traits related to muscle growth, fatness, meat quality and metabolism. We used 18 crossbred Iberian pigs with divergent postnatal growth patterns for whole genome sequencing and SNP discovery, with over 13 million variants being detected. We selected 1023 missense SNPs located on annotated genes and showing different allele frequencies between pigs with makerdly different growth patterns. We complemented this panel with 192 candidate SNPs obtained from literature mining and from muscle RNAseq data. The selected markers were genotyped in 480 Iberian × Duroc pigs from a commercial population, in which phenotypes were obtained, and an association study was performed for the 1005 successfully genotyped SNPs showing segregation. The results confirmed the effects of several known SNPs in candidate genes (such as LEPR, ACACA, FTO, LIPE or SCD on fatness, growth and fatty acid composition) and also disclosed interesting effects of new SNPs in less known genes such as LRIG3, DENND1B, SOWAHB, EPHX1 or NFE2L2 affecting body weight, average daily gain and adiposity at different ages, or KRT10, NLE1, KCNH2 or AHNAK affecting fatness and FA composition. The results provide a valuable basis for future implementation of marker-assisted selection strategies in swine and contribute to a better understanding of the genetic architecture of relevant traits.
Assuntos
Carne , Polimorfismo de Nucleotídeo Único , Animais , Ácidos Graxos/genética , Ácidos Graxos/metabolismo , Marcadores Genéticos , Estudo de Associação Genômica Ampla , Fenótipo , Suínos/genéticaRESUMO
The presence of pharmaceutical compounds (PhCs) in the effluents of wastewater treatment plants (WWTPs) is an ecological concern. The issue could be alleviated by trapping those substances by cyclodextrin (CD) polymers or photolyzing them by pulsed light (PL). Consequently, a sequential CD polymer/PL system was tested for the removal of PhCs. Firstly, a survey detected the presence of recurrent PhCs in the effluents of local WWTPs. Then, pure water was spiked with 21 PhCs, 100 µg/L each one. The three-dimensional network provides amphiphilic features to the CD polymer that reduced the pollutant concentration by 77 %. Sorption involves a plead of physical and chemical mechanisms hindering the establishment of a general removal model for all compounds. The performed simulations hint that the retention capacity mainly correlates with the computed binding energies, so that theoretical models are revealed as valuable tools for further improvements. The complementary action of PL rose the elimination to 91 %. The polymer can be reused at least 10 times for ibuprofen (model compound) removal, and was able to eliminate the ecotoxicity of an ibuprofen solution. Therefore, this novel sequential CD polymer/PL process seems to be an efficient alternative to eliminate PhCs from wastewater.
Assuntos
Ciclodextrinas , Preparações Farmacêuticas , Poluentes Químicos da Água , Celulose , Ciclodextrinas/toxicidade , Eliminação de Resíduos Líquidos , Águas Residuárias/análise , Água , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidadeRESUMO
Omphalocele is a congenital malformation of the abdominal wall consisting of a protrusion of the abdominal contents at the base of the umbilical cord. It has a high association with genetic and structural defects; however, if the latter is ruled out, its prognosis improves significantly. Prenatal diagnosis has a key role in this condition as omphalocele can be diagnosed by ultrasound in the first trimester scan, enabling a coordinated approach strategy to achieve the best perinatal results. We present a case report of a pregnant patient with a fetus having a giant omphalocele in which prenatal diagnosis played a decisive role, allowing the coordination of a multidisciplinary team, which was crucial in the immediate care of the newborn.
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Epilepsy is a common disease affecting between 1% and 2% of the general population. The incidence increases with age. Given the complicated etiology and pathogenesis of this disease, epileptic patients of all ages may require anesthesia. The perioperative care of these patients involves a number of special considerations, although the main issues to deal with are pharmacologic. This review gives an overview of the etiopathogenesis and pathophysiology of epilepsy and describes the general characteristics of antiepileptic drug therapy. The anesthetic implications of chronic treatment with antiepileptic agents and the interactions between these drugs and common anesthetics are discussed in more detail.
Assuntos
Anestesia , Anestésicos , Epilepsia , Procedimentos Cirúrgicos Operatórios , Adulto , Anestésicos/farmacologia , HumanosRESUMO
Precise classification of acute leukemia (AL) is crucial for adequate treatment. EuroFlow has previously designed an AL orientation tube (ALOT) to guide towards the relevant classification panel (T-cell acute lymphoblastic leukemia (T-ALL), B-cell precursor (BCP)-ALL and/or acute myeloid leukemia (AML)) and final diagnosis. Now we built a reference database with 656 typical AL samples (145 T-ALL, 377 BCP-ALL, 134 AML), processed and analyzed via standardized protocols. Using principal component analysis (PCA)-based plots and automated classification algorithms for direct comparison of single-cells from individual patients against the database, another 783 cases were subsequently evaluated. Depending on the database-guided results, patients were categorized as: (i) typical T, B or Myeloid without or; (ii) with a transitional component to another lineage; (iii) atypical; or (iv) mixed-lineage. Using this automated algorithm, in 781/783 cases (99.7%) the right panel was selected, and data comparable to the final WHO-diagnosis was already provided in >93% of cases (85% T-ALL, 97% BCP-ALL, 95% AML and 87% mixed-phenotype AL patients), even without data on the full-characterization panels. Our results show that database-guided analysis facilitates standardized interpretation of ALOT results and allows accurate selection of the relevant classification panels, hence providing a solid basis for designing future WHO AL classifications.
Assuntos
Leucemia Mieloide Aguda/patologia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Imunofenotipagem/métodos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Adulto JovemRESUMO
BACKGROUND: In 2003 a simple test to detect difficult intubation (DI) in patients underwent laryngeal microsurgery was described. The present study was conducted to validate the test. METHODS: Patients with laryngeal disease scheduled for laryngeal microsurgery were included. The variables evaluated were eleven parameters: Mallampati Score ≥III, thyromental distance <6.5cm, mouth opening <40mm, limitation of the temporomandibular joint, pathological dentition, arched paladet, maxillary deficiency, neck mobility <90°, body mass index, symptoms of laryngeal dysfunction, and tumour of supraglottic region. A rapid examination of the airway by an expert anaesthesiologist was carried out just before induction. DI was defined by a Cormack laryngeal view gradeiii-iv and/or if auxiliary equipment was required to achieve orotracheal intubation. A comparison of ROC curves was conducted to estimate the best predicting cut-off, as well as differences between the index described in 2003 and the rapid assessment by an expert anaesthesiologist. RESULTS: One hundred and five patients were included in the study. The incidence of DI according to the predefined criteria was 45% (47 patients). The score at the cut-off of 5 provides a sensitivity of 89% and a specificity of 55%. The fast-evaluation by an expert anaesthesiologist obtained similar sensitivity (89%) and better specificity (81%). Area under curve (AUC) was 0.87, similar to a fast evaluation (AUC: 0.85; P=.71). CONCLUSION: The index was validated at a cut-off of ≥5, being a useful and reliable test to predict DI in patients with laryngeal diseases and it is a useful tool for anaesthesiologists with conventional training.
Assuntos
Manuseio das Vias Aéreas/métodos , Obstrução das Vias Respiratórias/diagnóstico , Antropometria/métodos , Intubação Intratraqueal , Laringe/cirurgia , Microcirurgia , Índice de Gravidade de Doença , Adulto , Área Sob a Curva , Humanos , Laringoscopia , Exame Físico , Curva ROC , Medição de Risco , Sensibilidade e EspecificidadeRESUMO
The immunological bone marrow (BM) microenvironment plays a major role in controlling growth and survival of clonal plasma cells (PC); this might translate into different patterns of expression of molecules involved in immune responses on PC from different types of monoclonal gammopathies (MG). We have studied the expression of a group of nine such molecules on both BMPC and the plasma of 61 newly diagnosed MG patients (30 MG of undetermined significance (MGUS), 27 multiple myeloma (MM) and four plasma cell leukemia (PCL)) and five normal individuals. Clonal PC from all MG displayed significantly increased levels of CD56, CD86 and CD126, and decreased amounts of CD38 (P<0.001). Additionally, HLA-I and beta2-microglobulin were abnormally highly expressed in MGUS, while CD40 expression was decreased in MM and PCL (P<0.05). Interestingly, a progressive increase in the soluble levels of beta2-microglobulin was found from MGUS to MM and PCL patients (P=0.03). In contrast, all groups showed similar surface and soluble amounts of CD126, CD130 and CD95, except for increased soluble levels of CD95 observed in PCL. Overall, those phenotypic differences are consistent with increased antigen presentation and costimulatory capacities in MGUS, which progressively deteriorate in malignant MG (MM and PCL).
Assuntos
Antígenos CD/genética , Medula Óssea/patologia , Leucemia Plasmocitária/genética , Mieloma Múltiplo/genética , Paraproteinemias/imunologia , Plasmócitos/imunologia , Idoso , Antígenos CD/imunologia , Medula Óssea/imunologia , Células Clonais/imunologia , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Imunofenotipagem/métodos , Leucemia Plasmocitária/patologia , Masculino , Mieloma Múltiplo/patologia , Paraproteinemias/genética , Paraproteinemias/patologia , Plasmócitos/patologiaRESUMO
The concept of Developmental Origins of Health and Disease (DOHaD) addresses, from a large set of epidemiological evidences in human beings and translational studies in animal models, both the importance of genetic predisposition and the determinant role of maternal nutrition during pregnancy on adult morphomics and homeostasis. Compelling evidences suggest that both overnutrition and undernutrition may modify the intrauterine environment of the conceptus and may alter the expression of its genome and therefore its phenotype during prenatal and postnatal life. In fact, the DOHaD concept is an extreme shift in the vision of the factors conditioning adult phenotype and supposes a drastic change from a gene-centric perspective, only modified by lifestyle and nutritional strategies during juvenile development and adulthood, to a more holistic approach in which environmental, parental, and prenatal conditions are strongly determining postnatal development and homeostasis. The implications of DOHaD are profound in all the mammalian species and the present review summarizes current knowledge on causes and consequences of DOHaD in pigs, both for meat production and as a well-recognized model for biomedicine research.
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Efeitos Tardios da Exposição Pré-Natal , Doenças dos Suínos/prevenção & controle , Fenômenos Fisiológicos da Nutrição Animal , Animais , Feminino , Predisposição Genética para Doença , Gravidez , Suínos , Doenças dos Suínos/genéticaRESUMO
Acute administration of glucagon to the rat in vivo inhibits hepatic polypeptide chain elongation by about 30%. This effect was not observed in adrenalectomized rats, despite the significant increases in the hepatic content of cyclic AMP. Fatty acid administration mimics the glucagon action on protein synthesis; however, in adrenalectomized animals they were ineffective. Whether glucagon or fatty acids were administered, there was a significant increase in the state of reduction of the NAD system in normal as well as in adrenalectomized rats. This observation rules out the change in the cellular state of reduction as the mediator of their action on protein synthesis. A correlation was observed between the ability of glucagon or fatty acids to inhibit protein synthesis and to stimulate gluconeogenesis. An increased biosynthetic activity as reflected by an increased gluconeogenic flux is accompanied by a decreased phosphorylation state of adenine nucleotides that might be responsible for the inhibitory effect on protein synthesis. In adrenalectomized animals in which neither glucagon nor fatty acids stimulate gluconeogenesis, no effects on phosphorylation state or on the rate of protein synthesis were detected.
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Gluconeogênese , Fígado/metabolismo , Biossíntese de Proteínas , Nucleotídeos de Adenina/metabolismo , Adrenalectomia , Animais , Caprilatos/farmacologia , AMP Cíclico/farmacologia , Ácidos Graxos/farmacologia , Glucagon/farmacologia , Gluconeogênese/efeitos dos fármacos , Cinética , Fígado/efeitos dos fármacos , Masculino , NAD/metabolismo , Oxirredução , Fosforilação , Prednisolona/farmacologia , Ratos , Ratos EndogâmicosRESUMO
Calcium depletion induced by perfusing livers with calcium-free buffer did not alter the rates of basal glucose production from pyruvate or from increasing concentrations of lactate. However, calcium deficiency selectively prevented the fatty acid-induced stimulation of gluconeogenesis from lactate. This effect is not related to the higher NAD redox potential consistently observed in Ca2(+)-deficient livers. On the other hand, octanoate was capable of inducing dose-dependent changes in the [pyruvate]0.5 in calcium-depleted livers perfused with lactate, ruling out that low cellular calcium content could perturb the mitochondrial transport of pyruvate. The observation that the effect of calcium deficiency can be overcome by supraphysiological concentrations of pyruvate supports the proposal that stimulation of the maximal capacity of the gluconeogenic pathway by fatty acid relies largely on the tricarboxylic acid cycle activity, restricted in calcium deficiency conditions.
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Cálcio/metabolismo , Caprilatos/metabolismo , Gluconeogênese , Lactatos/metabolismo , Fígado/metabolismo , Piruvatos/metabolismo , Animais , Soluções Tampão , Cálcio/farmacologia , Caprilatos/farmacologia , Relação Dose-Resposta a Droga , Gluconeogênese/efeitos dos fármacos , Lactatos/farmacologia , Masculino , Perfusão , Piruvatos/farmacologia , Ratos , Ratos EndogâmicosRESUMO
This work reports the primary nucleotide structure and in vitro translation of a cDNA, expressed by a gene mapping on chromosome 12, that encodes a human hepatic alpha-glycerol-3-phosphate dehydrogenase (L-glycerol-3-phosphate:NAD oxidoreductase, E.C. 1.1.1.8). The 1413 bp cDNA comprises an ORF of 1050 bp that encodes a 349 amino acid protein of 37.5 kDa. Northern blot analysis of poly(A)+ mRNA from human liver showed three transcripts, while from human placenta only two transcripts were detected.
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Glicerolfosfato Desidrogenase/genética , Fígado/enzimologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar , Glicerol-3-Fosfato Desidrogenase (NAD+) , Glicerolfosfato Desidrogenase/química , Glicerolfosfato Desidrogenase/metabolismo , Humanos , Cinética , Dados de Sequência MolecularRESUMO
(1) The addition of long chain fatty acids to the incubation medium of isolated rat lung cells produced a dose-dependent inhibition of protein labelling from L-[3H]valine. Maximal rate changes were observed at fatty acids levels within the range of their physiological concentration. (2) The effect of fatty acids on protein labelling does not seem to be mediated by their oxidation. The following observations seem to support this conclusion: (a) the rate of fatty acid oxidation by lung cells was remarkably low, so that no significant variations in the state of reduction of the NAD system were detected; (b) there was no correspondence in the dose-response patterns of fatty acid oxidation and inhibition of protein labelling; (c) octanoate was much more actively oxidized than oleate, however the latter was more effective in decreasing protein labelling. (3) An apparent relationship between the length of the fatty chain and its ability to inhibit protein labelling seems to exist. The longer the chain the stronger the inhibitory effect observed. (4) The effect of fatty acid on protein labelling seems to be mediated by a cellular energy depletion secondary to an inhibition of the respiratory chain. Their ability to decrease oxygen uptake and adenine nucleotide content was also proportional to the chain length. (5) Glucose, which apparently acted by increasing energy production at substrate level phosphorylation, partially prevented the inhibitory effect of fatty acid on protein labelling. This observation supports the point of view that fatty acids do not act in decreasing protein labelling by perturbing directly the protein synthesis machinery but decreasing the phosphorylation potential.
Assuntos
Ácidos Graxos não Esterificados/metabolismo , Glucose/farmacologia , Pulmão/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Nucleotídeos de Adenina/metabolismo , Animais , Radioisótopos de Carbono , Metabolismo Energético/efeitos dos fármacos , Ácidos Graxos não Esterificados/farmacologia , Técnicas In Vitro , Cinética , Pulmão/efeitos dos fármacos , Masculino , Proteínas/genética , RatosRESUMO
(1) Glucose stimulates the incorporation of amino acids into protein in lung cells isolated by digestion of the lung stroma with collagenase. This effect reflects mainly an increase in protein synthesis since no effect of glucose had been found to the uptake of amino acid precursors and, although glucose decreases the rate of intracellular proteolysis by 15%, this effect cannot account for the increased incorporation of radioactivity into proteins. Furthermore, glucose did not induce any significant change in the intracellular content of valine. (2) For glucose to act on protein synthesis, it must be glycolyzed since its stereoisomer, L-glucose, which is not metabolized by lung cells, has no effect. (3) The mechanism of glucose action does not seem to be related simply to variations of cellular ATP content or energy charge. The following arguments seem to support this conclusion: (i) glucose does not bring about significant variations in the concentration of reactants of the adenylate system; (ii) the increase in protein synthesis induced by glucose in energy-depleted cells correlates with a rise in ATP content and energy charge; however, adenosine, which increases ATP levels in a form quantitatively similar to glucose, is unable to affect protein synthesis: (iii) glucose also accelerates the incorporation of amino acids into proteins in adenosine-treated lung cells in which the ATP concentration was almost double that of the control and the energy charge was considerably elevated, ruling out the possibility that a rise in the steady-state concentration of ATP and/or energy charge alone could be responsible for the acceleration of protein synthesis. (4) It can be concluded that the effect of glucose in increasing protein synthesis in lung cells is dependent on some signal arising from its breakdown and not to variations in the concentration of reactants or energy charge of the adenylate system.