151 resultados para muscle enzymes

em Scielo Saúde Pública - SP


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We measured bone mineral density (BMD) in girls with juvenile dermatomyositis (JDM) considering multiple factors in order to determine if it could be used as a predictor of reduction in bone mass. A cross-sectional study of lumbar spine BMD (L2-L4) was conducted on 10 girls aged 7-16 years with JDM. A group of 20 age-matched healthy girls was used as control. Lumbar spine BMD was measured by dual-energy X-ray absorptiometry. Weight, height and pubertal Tanner stage were determined in all patients and controls. Duration of disease and mean daily and cumulative steroid doses were calculated for all patients on the basis of their medical charts. JDM activity was determined on the basis of the presence of muscle weakness, cutaneous vasculitis and/or elevation of serum concentration of one or more skeletal muscle enzymes. Seven patients demonstrated osteopenia or osteoporosis. Lumbar BMD was significantly lower in the JDM patients than the age-matched healthy control girls (0.712 vs 0.878, respectively; Student t-test, P = 0.041). No significant correlation between BMD and age, height, Tanner stage, disease duration, corticosteroid use, or disease activity was observed in JDM girls, but a correlation was observed between BMD and weight (Pearson's correlation coefficient, r = 0.802). Patients with JDM may be at risk for a significant reduction in BMD that might contribute to further skeletal fragility. Our results suggest that reduced bone mass in JDM may be related to other intrinsic mechanisms in addition to steroid treatment and some aspects of the disease itself may contribute to this condition.

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Biochemical and hematimetric indicators of inflammation and cell damage were correlated with bilirubin and hepatic and pancreatic enzymes in 30 chronic male alcoholics admitted into psychiatric hospital for detoxification and treatment of alcoholism. Aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, alkaline phosphatase, and total bilirubin were altered, respectively, in 90%, 63%, 87%, 23% and 23% of the cases. None of the indicators of inflammation (lactic dehydrogenase, altered in 16% of the cases; alpha-1 globulin, 24%; alpha-2 globulin, 88%; leucocyte counts, 28%) was correlated with alterations of bilirubin or liver enzymes. Lactic dehydrogenase was poorly sensitive for detection of hepatocytic or muscular damage. Alterations of alpha-globulins seemed to have been due more to alcohol metabolism-induced increase of lipoproteins than to inflammation. Among indicators of cell damage, serum iron, increased in 40% of the cases, seemed to be related to liver damage while creatine phosphokinase, increased in 84% of the cases, related to muscle damage. Hyperamylasemia was found in 20% of the cases and significantly correlated with levels of bilirubin, alkaline phosphatase and gamma-glutamyltransferase. It was indicated that injuries of liver, pancreas, salivary glands, and muscle occurred in asymptomatic or oligosymptomatic chronic alcoholics.

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The modification of pyruvate kinase (PK) and lactate dehydrogenase (LDH) activity in foot muscle of the mussel Mytilus galloprovincialis during exposure to air and recovery in water was investigated. In the course of exposure to air, the activity of these enzymes measured at high and low substrate concentrations showed successive increases and decreases. Returning the mussels to water after exposure to air affected enzyme activity in a manner similar to anaerobiosis. When measuring at saturated concentrations of substrates and substrate and coenzyme for PK and LDH, respectively, the maximum activation of PK (37%) was observed at 4 h of animal exposure to air, and for LDH (67%) at 6 h exposure to air. During 24 h of exposure of animals to air, PK activity practically reached the stock level, while LDH was still activated (148%). The change in lactate dehydrogenase activity in mussel muscle during anoxia and recovery is described here for the first time. Variation in pyruvate kinase activity during exposure to air and recovery is linked to the alteration of half-maximal saturation constants and maximal velocity for both substrates. The possible role of reversible phosphorylation in the regulation of pyruvate kinase and lactate dehydrogenase properties is discussed

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The effect of hypoxia on the levels of glycogen, glucose and lactate as well as the activities and binding of glycolytic and associated enzymes to subcellular structures was studied in brain, liver and white muscle of the teleost fish, Scorpaena porcus. Hypoxia exposure decreased glucose levels in liver from 2.53 to 1.70 µmol/g wet weight and in muscle led to its increase from 3.64 to 25.1 µmol/g wet weight. Maximal activities of several enzymes in brain were increased by hypoxia: hexokinase by 23%, phosphoglucoisomerase by 47% and phosphofructokinase (PFK) by 56%. However, activities of other enzymes in brain as well as enzymes in liver and white muscle were largely unchanged or decreased during experimental hypoxia. Glycolytic enzymes in all three tissues were partitioned between soluble and particulate-bound forms. In several cases, the percentage of bound enzymes was reduced during hypoxia; bound aldolase in brain was reduced from 36.4 to 30.3% whereas glucose-6-phosphate dehydrogenase fell from 55.7 to 28.7% bound. In muscle PFK was reduced from 57.4 to 41.7% bound. Oppositely, the proportion of bound aldolase and triosephosphate isomerase increased in hypoxic muscle. Phosphoglucomutase did not appear to occur in a bound form in liver and bound phosphoglucomutase disappeared in muscle during hypoxia exposure. Anoxia exposure also led to the disappearance of bound fructose-1,6-bisphosphatase in liver, whereas a bound fraction of this enzyme appeared in white muscle of anoxic animals. The possible function of reversible binding of glycolytic enzymes to subcellular structures as a regulatory mechanism of carbohydrate metabolism is discussed.

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The effects of short-term burst (5 min at 1.8 m/s) swimming and long-term cruiser (60 min at 1.2 m/s) swimming on maximal enzyme activities and enzyme distribution between free and bound states were assessed for nine glycolytic and associated enzymes in tissues of horse mackerel, Trachurus mediterraneus ponticus. The effects of exercise were greatest in white muscle. The activities of phosphofructokinase (PFK), pyruvate kinase (PK), fructose-1,6-bisphosphatase (FBPase), and phosphoglucomutase (PGM) all decreased to 47, 37, 37 and 67%, respectively, during 60-min exercise and all enzymes except phosphoglucoisomerase (PGI) and PGM showed a change in the extent of binding to subcellular particulate fractions during exercise. In red muscle, exercise affected the activities of PGI, FBPase, PFK, and lactate dehydrogenase (LDH) and altered percent binding of only PK and LDH. In liver, exercise increased the PK activity 2.3-fold and reduced PGI 1.7-fold only after 5 min of exercise but altered the percent binding of seven enzymes. Fewer effects were seen in brain, with changes in the activities of aldolase and PGM and in percent binding of hexokinase, PFK and PK. Changes in enzyme activities and in binding interactions with subcellular particulate matter appear to support the altered demands of tissue energy metabolism during exercise.

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Blue native polyacrylamide electrophoresis (BN-PAGE) is a technique developed for the analysis of membrane complexes. Combined with histochemical staining, it permits the analysis and quantification of the activities of mitochondrial oxidative phosphorylation enzymes using whole muscle homogenates, without the need to isolate muscle mitochondria. Mitochondrial complex activities were measured by emerging gels in a solution containing all specific substrates for NADH dehydrogenase and cytochrome c oxidase enzymes (complexes I and IV, respectively) and the colored bands obtained were measured by optique densitometry. The objective of the present study was the application of BN-PAGE colorimetric staining for enzymatic characterization of mitochondrial complexes I and IV in rat muscles with different morphological and biochemical properties. We also investigated these activities at different times after acute exercise of rat soleus muscle. Although having fewer mitochondria than oxidative muscles, white gastrocnemius muscle presented a significantly higher activity (26.7 ± 9.5) in terms of complex I/V ratio compared to the red gastrocnemius (3.8 ± 0.65, P < 0.05) and soleus (9.8 ± 0.9, P < 0.001) muscles. Furthermore, the complex IV/V ratio of white gastrocnemius muscle was always significantly higher when compared to the other muscles. Ninety-five minutes of exhaustive physical exercise induced a decrease in complex I/V and complex IV/V ratios after all resting times (0, 3 and 6 h) compared to control (P < 0.05), probably reflecting the oxidative damage due to increasing free radical production in mitochondria. These results demonstrate the possible and useful application of BN-PAGE-histochemical staining to physical exercise studies.

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Angiotensin-converting enzymes 1 (ACE1) and 2 (ACE2) are key enzymes of the renin-angiotensin system, which act antagonistically to regulate the levels of angiotensin II (Ang II) and Ang-(1-7). Considerable data show that ACE1 acts on normal skeletal muscle functions and architecture. However, little is known about ACE1 levels in muscles with different fiber compositions. Furthermore, ACE2 levels in skeletal muscle are not known. Therefore, the purpose of this study was to characterize protein expression and ACE1 and ACE2 activities in the soleus and plantaris muscles. Eight-week-old female Wistar rats (N = 8) were killed by decapitation and the muscle tissues harvested for biochemical and molecular analyses. ACE1 and ACE2 activities were investigated by a fluorometric method using Abz-FRK(Dnp)P-OH and Mca-YVADAPK(Dnp)-OH fluorogenic substrates, respectively. ACE1 and ACE2 protein expression was analyzed by Western blot. ACE2 was expressed in the skeletal muscle of rats. There was no difference between the soleus (type I) and plantaris (type II) muscles in terms of ACE2 activity (17.35 ± 1.7 vs 15.09 ± 0.8 uF·min-1·mg-1, respectively) and protein expression. ACE1 activity was higher in the plantaris muscle than in the soleus (71.5 ± 3.9 vs 57.9 ± 1.1 uF·min-1·mg-1, respectively). Moreover, a comparative dose-response curve of protein expression was established in the soleus and plantaris muscles, which indicated higher ACE1 levels in the plantaris muscle. The present findings showed similar ACE2 levels in the soleus and plantaris muscles that might result in a similar Ang II response; however, lower ACE1 levels could attenuate Ang II production and reduce bradykinin degradation in the soleus muscle compared to the plantaris. These effects should enhance the aerobic capacity necessary for oxidative muscle activity.

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We examined the capacity of high-intensity intermittent training (HI-IT) to facilitate the delivery of lipids to enzymes responsible for oxidation, a task performed by the carnitine palmitoyl transferase (CPT) system in the rat gastrocnemius muscle. Male adult Wistar rats (160-250 g) were randomly distributed into 3 groups: sedentary (Sed, N = 5), HI-IT (N = 10), and moderate-intensity continuous training (MI-CT, N = 10). The trained groups were exercised for 8 weeks with a 10% (HI-IT) and a 5% (MI-CT) overload. The HI-IT group presented 11.8% decreased weight gain compared to the Sed group. The maximal activities of CPT-I, CPT-II, and citrate synthase were all increased in the HI-IT group compared to the Sed group (P < 0.01), as also was gene expression, measured by RT-PCR, of fatty acid binding protein (FABP; P < 0.01) and lipoprotein lipase (LPL; P < 0.05). Lactate dehydrogenase also presented a higher maximal activity (nmol·min-1·mg protein-1) in HI-IT (around 83%). We suggest that 8 weeks of HI-IT enhance mitochondrial lipid transport capacity thus facilitating the oxidation process in the gastrocnemius muscle. This adaptation may also be associated with the decrease in weight gain observed in the animals and was concomitant to a higher gene expression of both FABP and LPL in HI-IT, suggesting that intermittent exercise is a "time-efficient" strategy inducing metabolic adaptation.

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The objective of the present study was to investigate the effects of eccentric training on the activity of mitochondrial respiratory chain enzymes, oxidative stress, muscle damage, and inflammation of skeletal muscle. Eighteen male mice (CF1) weighing 30-35 g were randomly divided into 3 groups (N = 6): untrained, trained eccentric running (16°; TER), and trained running (0°) (TR), and were submitted to an 8-week training program. TER increased muscle oxidative capacity (succinate dehydrogenase and complexes I and II) in a manner similar to TR, and TER did not decrease oxidative damage (xylenol and creatine phosphate) but increased antioxidant enzyme activity (superoxide dismutase and catalase) similar to TR. Muscle damage (creatine kinase) and inflammation (myeloperoxidase) were not reduced by TER. In conclusion, we suggest that TER improves mitochondrial function but does not reduce oxidative stress, muscle damage, or inflammation induced by eccentric contractions.

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A significantly diminished antibody response to hepatitis B vaccine has been demonstrated in adults when the buttock is used as the injection site. However, in Brazil, the buttock continues to be recommended as site of injection for intramuscular administration of vaccines in infants. In this age group, there are no controlled studies evaluating the immunogenicity of the hepatitis B vaccine when administered at this site. In the present study, 258 infants were randomized to receive the hepatitis B vaccine either in the buttock (n = 123) or in the anterolateral thigh muscle (n = 135). The immunization schedule consisted of three doses of hepatitis B vaccine (Engerix Bâ, 10 mug) at 2, 4 and 9 months of age. There were no significant differences in the proportion of seroconversion (99.3% x 99.2%), or in the geometric mean titer of ELISA anti-HBs (1,862.1 x 1,229.0 mIU/mL) between the two groups. This study demonstrates that a satisfactory serological response can be obtained when the hepatitis B vaccine is administered intramuscularly into the buttock.

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Out of the twenty-four samples of shrimp and fish muscle used for this study, twelve were collected near a large marine sewer for waste disposal, 3 km off the coast of Fortaleza (Brazil) and used for the isolation of E. coli. Other twelve were collected at the Mucuripe fresh fish market (Fortaleza, Brazil) and used for the isolation of Staphylococcus aureus. Ethanol, water and acetone-diluted extracts of guava and papaya leaf sprouts were tested on the bacteria in order to verify their microbicidal potential. The E. coli strains used in the trials were rated LT positive. The papaya leaf extracts (Carica papaya Linn) showed no microbicidal activity while the guava sprout extracts (Psidium guajava Linn) displayed halos exceeding 13 mm for both species, an effect considered to be inhibitory by the method employed. Guava sprout extracts by 50% diluted ethanol most effectively inhibited E. coli (EPEC), while those in 50% acetone were less effective. It may be concluded that guava sprout extracts constitute a feasible treatment option for diarrhea caused by E. coli or by S. aureus-produced toxins, due to their quick curative action, easy availability in tropical countries and low cost to the consumer.

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The gelatinase, urease, lipase, phospholipase and DNase activities of 11 chromoblastomycosis agents constituted by strains of Fonsecaea pedrosoi, F. compacta, Phialophora verrucosa, Cladosporium carrionii, Cladophialophora bantiana and Exophiala jeanselmei were analyzed and compared. All strains presented urease, gelatinase and lipase activity. Phospholipase activity was detected only on five of six strains of F. pedrosoi. DNase activity was not detected on the strains studied. Our results indicate that only phospholipase production, induced by egg yolk substrate, was useful for the differentiation of the taxonomically related species studied, based on their enzymatic profile.

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INTRODUCTION: This study evaluated the degree of disability, pain levels, muscle strength, and electromyographic function (RMS) in individuals with leprosy. METHODS: We assessed 29 individuals with leprosy showing common peroneal nerve damage and grade 1 or 2 disability who were referred for physiotherapeutic treatment, as well as a control group of 19 healthy participants without leprosy. All subjects underwent analyses of degree of disability, electromyographic tests, voluntary muscle force, and the Visual Analog Pain Scale. RESULTS: McNemar's test found higher levels of grade 2 of disability (Δ = 75.9%; p = 0.0001) among individuals with leprosy. The Mann-Whitney test showed greater pain levels (Δ = 5.0; p = 0.0001) in patients with leprosy who had less extension strength in the right and left extensor hallucis longus muscles (Δ = 1.28, p = 0.0001; Δ = 1.55, p = 0.0001, respectively) and dorsiflexion of the right and left feet (Δ = 1.24, p = 0.0001; Δ = 1.45, p = 0.0001, respectively) than control subjects. The Kruskal-Wallis test showed that the RMS score for dorsiflexion of the right (Δ = 181.66 m·s-2, p = 0.001) and left (Δ = 102.57m·s-2, p = 0.002) feet was lower in patients with leprosy than in control subjects, but intragroup comparisons showed no difference. CONCLUSIONS: Leprosy had a negative influence on all of the study variables, indicating the need for immediate physiotherapeutic intervention in individuals with leprosy. This investigation opens perspectives for future studies that analyze leprosy treatment with physical therapeutic intervention.

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The contribution of the sternocleidomastoid branch of the occipital artery (superior arterial pedicle - SAP) to the irrigation of the sternocleidomastoid muscle (SCM) was evaluated in fresh human cadavers by injecting radiological dye and a resin for microvasculature corrosion casts. From its insertion in the mastoid process of the temporal bone, the SCM was divided into superior, medium, and inferior thirds. In most of the SCM, The SAP are formed by two longitudinal parallel branches. In all specimens, the radiological dye injected into the SAP reached or trespassed the middle part of the studied SCM. The SAP was poorly distributed in the lowermost region of the inferior third of the SCM, suggesting the contribution of other arteries or pedicles. The corrosion casts of the microvasculature showed a profuse network of microscopic vessels in those levels where the SAP was detected.

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PURPOSE: To measure the thickness of adductor pollicis muscle in healthy adults. This measurement will be used as a nutritional anthropometric parameter in further studies. SUBJECTS AND METHOD: Four hundred and twenty-one healthy adults were studied, 209 men and 212 women, with ages ranging from 18 to 87 years, living in Rio de Janeiro. The adductor pollicis muscle was also studied in the human anatomy lab as well as in normal healthy volunteers using CAT scans and nuclear magnetic resonance imaging to ensure that only the adductor pollicis was included in measurement of muscle thickness with a Lange caliper. To standardize the measurement, the methodology was detailed, with subjects sitting with the dominant hand dangling over the homolateral thigh and the elbow bent at approximately a 90° angle. The Lange caliper was applied at a pressure of 10 g/mm², pinching the adductor pollicis muscle at the vertex of an imaginary angle between the thumb and the index finger. The average of 3 consecutive measurements was considered to be the muscle thickness. RESULTS: This study provides the first estimates of adductor pollicis thickness in normal healthy subjects as an anthropometric parameter. The normal values in the dominant hand for men were 12.5 ± 2.8 mm (mean ± SD), median 12 mm, and for women were 10.5 ± 2.3 mm, median 10 mm.