RESUMEN
A general analysis of the behaviour of Cebus shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.(AU)
Uma análise geral do comportamento do Cebus apella mostra que este primata quando desloca para se alimentar ou realizar outra atividade apresenta diferentes maneiras de locomoção. Estas informações mostram que o músculo bíceps braquial deste animal é usado freqüentemente nas suas atividades de locomoção, mas deve ser lembrado ainda que este músculo é usado também para desenvolvimento de outras atividades como esconder-se, procurar objetos, vasculhar arboredos, além de cavar o chão. Considerando-se o exposto acima decidiu-se pesquisar as características histoenzimológicas do músculo bíceps braquial do macaco-prego com o objetivo de comparar se este músculo esta melhor adaptado para funções posturais ou fásicas. As amostras foram retiradas das regiões superficiais e profundas; inserções proximais (medial e lateral) e distal de seis macacos-prego machos e adultos, os quais foram submetidos às reações de m-ATPase, NADH-Tr. Baseado nos resultados das reações, as fibras foram classificadas em Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) e Slow Twitch (SO). Quanto à área dos diferentes tipos de fibras, os resultados encontrados foram semelhantes em todas as amostras estudadas, e as fibras de contração rápida foram sempre maiores do que as de contração lenta (FG=FOG>SO). Os dados obtidos sobre a frequência foram: nas três regiões superficiais estudadas FOG=FG>SO; nas regiões profundas das inserções proximais FOG=FG=SO e na inserção distal FOG>FG=SO. Baseado nestes dados pode-se concluir que o músculo bíceps braquial do macaco-prego está bem adaptado tanto para atividades posturais como fásicas.(AU)
Asunto(s)
Animales , Masculino , Brazo/fisiología , Cebus/metabolismo , Fibras Musculares Esqueléticas/enzimología , Brazo/inervación , Cebus/clasificación , Cebus/fisiología , Histocitoquímica , Locomoción , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/fisiología , Fibras Musculares Esqueléticas/fisiología , Fibras Musculares de Contracción Lenta/enzimología , Fibras Musculares de Contracción Lenta/fisiologíaRESUMEN
A general analysis of the behaviour of “Cebus” shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.
Uma análise geral do comportamento do “Cebus apella” mostra que este primata quando desloca para se alimentar ou realizar outra atividade apresenta diferentes maneiras de locomoção. Estas informações mostram que o músculo bíceps braquial deste animal é usado freqüentemente nas suas atividades de locomoção, mas deve ser lembrado ainda que este músculo é usado também para desenvolvimento de outras atividades como esconder-se, procurar objetos, vasculhar arboredos, além de cavar o chão. Considerando-se o exposto acima decidiu-se pesquisar as características histoenzimológicas do músculo bíceps braquial do macaco-prego com o objetivo de comparar se este músculo esta melhor adaptado para funções posturais ou fásicas. As amostras foram retiradas das regiões superficiais e profundas; inserções proximais (medial e lateral) e distal de seis macacos-prego machos e adultos, os quais foram submetidos às reações de m-ATPase, NADH-Tr. Baseado nos resultados das reações, as fibras foram classificadas em Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) e Slow Twitch (SO). Quanto à área dos diferentes tipos de fibras, os resultados encontrados foram semelhantes em todas as amostras estudadas, e as fibras de contração rápida foram sempre maiores do que as de contração lenta (FG=FOG>SO). Os dados obtidos sobre a frequência foram: nas três regiões superficiais estudadas FOG=FG>SO; nas regiões profundas das inserções proximais FOG=FG=SO e na inserção distal FOG>FG=SO. Baseado nestes dados pode-se concluir que o músculo bíceps braquial do macaco-prego está bem adaptado tanto para atividades posturais como fásicas.
Asunto(s)
Animales , Masculino , Brazo/fisiología , Cebus/metabolismo , Fibras Musculares Esqueléticas/enzimología , Brazo/inervación , Cebus/clasificación , Cebus/fisiología , Histocitoquímica , Locomoción , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/fisiología , Fibras Musculares Esqueléticas/fisiología , Fibras Musculares de Contracción Lenta/enzimología , Fibras Musculares de Contracción Lenta/fisiologíaRESUMEN
Myotoxic effects related to intracellular Ca(2+) disturbances have been reported for local anesthetics. Such effects might derive from Ca-ATPase dysfunction. The aim of this work was to describe the effect of lidocaine and bupivacaine on the sarcoplasmic reticulum (SR) Ca-ATPase from fast-twitch skeletal muscle and to identify the affected steps of the enzyme's cycle. SR sealed vesicles were isolated from rabbit fast-twitch muscles by ultracentrifugation. The effect of the anesthetics on Ca-ATPase activity was assessed with a colorimetric method and Ca(2+) binding, uptake, phosphorylation of the enzyme by ATP, Ca(2+) dissociation kinetics and phosphoenzyme formation and decomposition levels were tested with radioisotopic methods. Lidocaine and bupivacaine inhibited Ca-ATPase activity with half-maximal inhibitory concentrations (Ki) of 25.3 and 31.4 mM, respectively, and the steady-state Ca(2+) transport ability with Ki values of 33.6 and 46.5 mM, decreasing the maximal transport rate without modification of the Ca(2+) or ATP affinity for the enzyme. This is consistent with an absence of competition for the transport and catalytic sites. The anesthetics did not inhibit Ca(2+) binding but inhibited the phosphorylation partial reactions. Ca(2+) dissociation kinetics was not affected, but the phosphoenzyme levels were decreased, and the decomposition rate of the phosphoenzyme became faster in the presence of the anesthetics. It is concluded that lidocaine and bupivacaine at concentrations available in pharmaceutical formulations for clinical medical and dental uses inhibit the SR Ca-ATPase through inhibition of key phosphorylation steps of the enzymatic cycle.
Asunto(s)
Anestésicos Locales/farmacología , Bupivacaína/farmacología , Lidocaína/farmacología , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/antagonistas & inhibidores , Animales , Masculino , Fibras Musculares de Contracción Rápida/enzimología , Conejos , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/metabolismoRESUMEN
The aim of this study was to characterize the sarcoplasmic-endoplasmic reticulum Ca-ATPase (SERCA) isoforms in rabbit masticatory muscles compared with those in fast-twitch muscle. It was hypothesized that combined expression of the SERCA isoforms in fast- and slow-twitch muscles accounts for lower Ca-ATPase activity. SERCA was isolated by differential centrifugation, the isoforms were determined by ELISA, and the activity of each isoform was measured using a colorimetric method. Activity was tested for significance by anova, and the distribution of isoforms was assessed using the chi-square test (P < 0.05) and correlated to SERCA activity using Spearman's rank correlation. SERCA1 was predominant (90.5%) in fast-twitch muscle, whereas a mixture of SERCA isoforms was found in masticatory muscles: 62-78% was SERCA2, 20-37% was SERCA1, and the SERCA3 content was negligible. Depressor muscles showed a significantly higher content (77.8%) of SERCA2, and elevator muscles showed a higher content (35.4%) of SERCA1. Elevator muscles showed higher expression of SERCA2a (58%), and depressor muscles showed higher expression of SERCA2b (20%). The SERCA1 content was mainly SERCA1a and significantly higher for elevator muscles (33%), whereas depressor muscles showed a higher content of SERCA1b (4%). The SERCA1 content of fast-twitch muscle was mainly SERCA1a (88.5%). It is concluded that the mixture of different SERCA isoforms, along with a substantial content of SERCA2b, in masticatory muscles would support lower Ca-ATPase activity and calcium transport.
Asunto(s)
Músculos Masticadores/enzimología , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/análisis , Animales , Electroforesis en Gel de Poliacrilamida , Ensayo de Inmunoadsorción Enzimática , Isoenzimas/análisis , Isoenzimas/clasificación , Masculino , Músculo Masetero/enzimología , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Lenta/enzimología , Músculos del Cuello/enzimología , Músculos Pterigoideos/enzimología , Conejos , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/clasificación , Músculo Temporal/enzimologíaRESUMEN
AIMS: Differences in fibre-type composition of skeletal muscle have been associated with obesity and insulin resistance. As a poor nutrient environment early in life is a predisposing factor for the development of obesity and related metabolic diseases at adulthood, this study aimed at determining the long-term consequences of maternal undernutrition on the structural and metabolic properties of two skeletal muscles characterized by their different fibre-type composition and metabolic properties. METHODS: The fibre-type composition and enzymatic activities of hexokinase (HK), beta-hydroxyacyl-CoA dehydrogenase (ß-HAD) and citrate synthase (CS) were measured in soleus and extensor digitorum longus (EDL) muscles from adult rats born to dams fed a control (17% protein) or a low-protein [8% protein (PR)] diet throughout pregnancy and lactation. In addition, the expression levels of several genes regulating glycolysis, fatty acid oxidation and mitochondrial biogenesis were determined by real-time PCR. RESULTS: Protein rats exhibited enhanced density of type II fibres along with decreased rate of fatty acid oxidation and glycolysis in soleus but not EDL. Malnourished rats exhibited also a different gene expression profile in soleus and EDL. Altogether, these alterations correspond to a state of energy deficiency and are present in animals which do not show yet any sign of obesity or glucose intolerance. CONCLUSION: We conclude that maternal protein restriction alters in the long term the structural and enzymatic properties of offspring skeletal muscle in a fibre-type-dependent manner. These alterations might have a causative role in the development of obesity and related metabolic disorders later in life.
Asunto(s)
Envejecimiento/metabolismo , Dieta con Restricción de Proteínas , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/patología , Fibras Musculares de Contracción Lenta/enzimología , Fibras Musculares de Contracción Lenta/patología , Proteínas Musculares/metabolismo , 3-Hidroxiacil-CoA Deshidrogenasas/metabolismo , Envejecimiento/patología , Animales , Citrato (si)-Sintasa/metabolismo , Proteínas en la Dieta/metabolismo , Femenino , Hexoquinasa/metabolismo , Masculino , Ratas , Ratas WistarRESUMEN
A general analysis of the behaviour of "Cebus" shows that when this primate moves position to feed or perform another activity, it presents different ways of locomotion. This information shows that the brachial biceps muscle of this animal is frequently used in their locomotion activities, but it should also be remembered that this muscle is also used for other development activities like hiding, searching for objects, searching out in the woods, and digging in the soil. Considering the above, it was decided to research the histoenzimologic characteristics of the brachial biceps muscle to observe whether it is better adpted to postural or phasic function. To that end, samples were taken from the superficial and deep regions, the inserts proximal (medial and lateral) and distal brachial biceps six capuchin monkeys male and adult, which were subjected to the reactions of m-ATPase, NADH-Tr. Based on the results of these reactions fibres were classified as in Fast Twitch Glycolitic (FG), Fast Twitch Oxidative Glycolitic (FOG) and Slow Twitc (SO). In general, the results, considering the muscle as a whole, show a trend of frequency FOG> FG> SO. The data on the frequency were studied on three superficial regions FOG=FG>SO; the deep regions of the inserts proximal FOG=FG=SO and inserting the distal FOG>FG=SO. In conclusion, the biceps brachii of the capuchin monkey is well adapted for both postural and phasic activities.
Asunto(s)
Brazo/fisiología , Cebus/metabolismo , Fibras Musculares Esqueléticas/enzimología , Animales , Brazo/inervación , Cebus/clasificación , Cebus/fisiología , Histocitoquímica , Locomoción , Masculino , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/fisiología , Fibras Musculares Esqueléticas/fisiología , Fibras Musculares de Contracción Lenta/enzimología , Fibras Musculares de Contracción Lenta/fisiologíaRESUMEN
The muscle fiber phenotype is mainly determined by motoneuron innervation and changes in neuromuscular interaction alter the muscle fiber type. In dystrophin-deficient mdx mice, changes in the molecular assembly of the neuromuscular junction and in nerve terminal sprouting occur in the sternomastoid (STN) muscle during early stages of the disease. In this study, we were interested to see whether early changes in neuromuscular assembly are correlated with alterations in fiber type in dystrophic STN at 2 months of age. A predominance of hybrid fast myofibers (about 52% type IIDB) was observed in control (C57Bl/10) STN. In mdx muscle, the lack of dystrophin did not change this profile (about 54% hybrid type IIDB). Pure fast type IID fibers predominated in normal and dystrophic diaphragm (DIA; about 39% in control and 30% in mdx muscle) and a population of slow Type I fibers was also present (about 10% in control and 13% in mdx muscle). In conclusion, early changes in neuromuscular assembly do not affect the fiber type composition of dystrophic STN. In contrast to the pure fast fibers of the more affected DIA, the hybrid phenotype of the STN may permit dynamic adaptations during progression of the disease.
Asunto(s)
Distrofina/deficiencia , Fibras Musculares de Contracción Rápida/citología , Fibras Musculares de Contracción Lenta/citología , Adaptación Fisiológica , Adenosina Trifosfatasas/metabolismo , Animales , Diafragma/citología , Distrofina/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Lenta/enzimologíaRESUMEN
Methyl parathion (MP), an organophosphate widely applied in agriculture and aquaculture, induces oxidative stress due to free radical generation and changes in the antioxidant defense system. The antioxidant roles of selenium (Se) were evaluated in Brycon cephalus exposed to 2 mg L(-1) of Folisuper 600 BR (MP commercial formulation - MPc, 600 g L(-1)) for 96 h. Catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione S-transferase (GST), reduced glutathione (GSH) and lipid peroxidation (LPO) levels in the gills, white muscle and liver were evaluated in fish fed on diets containing 0 or 1.5 mg Se kg(-1) for 8 weeks. In fish treated with a Se-free diet, the MPc exposure increased SOD and CAT activities in all tissues. However, the GPx activity decreased in white muscle and gills whereas no alterations were observed in the liver. MPc also increased GST activity in all tissues with a concurrent decrease in GSH levels. LPO values increased in white muscle and gills and did not change in liver after MPc exposure. A Se-supplemented diet reversed these findings, preventing increases in LPO levels and concurrent decreases in GPx activity in gills and white muscle. Similarly, GSH levels were maintained in all tissue after MPc exposure. These results suggest that dietary Se supplementation protects cells against MPc-induced oxidative stress.
Asunto(s)
Antioxidantes/farmacología , Suplementos Dietéticos , Peces/metabolismo , Insecticidas/toxicidad , Metil Paratión/toxicidad , Estrés Oxidativo/efectos de los fármacos , Selenito de Sodio/farmacología , Contaminantes Químicos del Agua/toxicidad , Alimentación Animal , Animales , Biomarcadores/metabolismo , Catalasa/metabolismo , Branquias/efectos de los fármacos , Branquias/enzimología , Glutatión/metabolismo , Glutatión Peroxidasa/metabolismo , Glutatión Transferasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/enzimología , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Fibras Musculares de Contracción Rápida/enzimología , Superóxido Dismutasa/metabolismoRESUMEN
We have studied the effects of mitochondria poisoning by carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP) on Ca(2+) signaling in enzymatically dissociated mouse flexor digitorum brevis (FDB) muscle fibers. We used Fura-2AM to measure resting [Ca(2+)](i) and MagFluo-4AM to measure Ca(2+) transients. Exposure to FCCP (2 microM, 2 min) caused a continuous increase in [Ca(2+)](i) at a rate of 0.60 nM/s and a drastic reduction of electrically elicited Ca(2+) transients without much effect on their decay phase. Half of the maximal effect occurred at [Ca(2+)](i) = 220 nM. This effect was partially reversible after long recuperation and was not diminished by Tiron, a reactive oxygen species (ROS) scavenger. FCCP had no effects on fiber excitability as shown by the generation of action potentials. 4CmC, an agonist of ryanodine receptors, induced a massive Ca(2+) release. FCCP diminished the rate but not the amount of Ca(2+) released, indicating that depletion of Ca(2+) stores did not cause the decrease in Ca(2+) transient amplitude. Ca(2+) transient amplitude could also be diminished, but to a lesser degree, by increases in [Ca(2+)](i) induced by repetitive stimulation of fibers treated with ciclopiazonic acid. This suggests an important role for Ca(2+) in the FCCP effect on transient amplitude.
Asunto(s)
Señalización del Calcio/efectos de los fármacos , Carbonil Cianuro p-Trifluorometoxifenil Hidrazona/toxicidad , Mitocondrias Musculares/efectos de los fármacos , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Desacopladores/toxicidad , Sal Disódica del Ácido 1,2-Dihidroxibenceno-3,5-Disulfónico/farmacología , Potenciales de Acción , Animales , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , ATPasas Transportadoras de Calcio/metabolismo , Cresoles/farmacología , Inhibidores Enzimáticos/farmacología , Colorantes Fluorescentes , Depuradores de Radicales Libres/farmacología , Fura-2/análogos & derivados , Indoles/farmacología , Cinética , Ratones , Microscopía Fluorescente/métodos , Mitocondrias Musculares/metabolismo , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/metabolismo , Músculo Esquelético/enzimología , Músculo Esquelético/metabolismo , Canal Liberador de Calcio Receptor de Rianodina/metabolismoRESUMEN
The effect of combined-factors (hypoxia+copper) on the biochemical parameters and antioxidant defenses were studied in the neotropical fish Piaractus mesopotamicus. Fish were exposed for 48 h to 0.4 mg Cu(2+) L(-1) (0.4Cu), hypoxia=50 mm Hg (Hpx), and 0.4 mg Cu(2) L(-1)+hypoxia=50 mm Hg (0.4CuHpx). The exposure to 0.4Cu increased the reactive oxygen species (ROS) in the liver, accompanied by increases in superoxide dismutase (SOD) and decreases in catalase (CAT) activity, showing the influence of copper in this protection. The exposure to Hpx decreased the activity of glutathione peroxidase (GSH-Px) and CAT. Exposure to a combined-factor caused an increase in the ROS production followed by an increase in SOD and a decrease in GSH-Px and CAT. At 0.4Cu, fish presented a reduction in CAT, while in Hpx decreases in SOD, CAT and GSH-Px were observed in red muscles. Single-factors were insufficient to cause ROS production. In combined-factors, increased ROS formation and decreased SOD, CAT and GSH-Px were observed. RBC increased in all groups, but only under combined-factors was there an increase in hemoglobin. Copper plasma concentration increased in groups exposed to copper. Na(+)/K(+)-ATPase activity in gills decreased in 0.4Cu and 0.4CuHpx, and increased in Hpx. Metallothionein concentration in gills increased under combined-factors. Combined-factors caused significant disturbances in the antioxidant defenses and biochemical parameters than single-factors.
Asunto(s)
Antioxidantes/metabolismo , Sulfato de Cobre/toxicidad , Peces/metabolismo , Branquias/efectos de los fármacos , Hipoxia/metabolismo , Hígado/efectos de los fármacos , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Animales , Catalasa/metabolismo , Sulfato de Cobre/sangre , Recuento de Eritrocitos , Proteínas de Peces/metabolismo , Branquias/enzimología , Branquias/metabolismo , Glutatión Peroxidasa/metabolismo , Hipoxia/sangre , Hipoxia/enzimología , Hígado/enzimología , Hígado/metabolismo , Metalotioneína/metabolismo , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/metabolismo , Especies Reactivas de Oxígeno/metabolismo , ATPasa Intercambiadora de Sodio-Potasio/metabolismo , Superóxido Dismutasa/metabolismo , Contaminantes Químicos del Agua/sangreRESUMEN
Silver catfish (Rhamdia quelen; Teleostei) were exposed to commercial formulation Roundup, a glyphosate herbicide: 0 (control), 0.2 or 0.4 mg/L for 96 h. Fish exposed to glyphosate showed an increase in hepatic glycogen, but a reduction in muscle glycogen at both concentrations tested. Glucose decreased in liver and increased in muscle of fish at both herbicide concentrations. Glyphosate exposure increased lactate levels in liver and white muscle at both concentrations. Protein levels increased in liver and decreased in white muscle while levels of ammonia in both tissues increased in fish at both glyphosate concentrations. Specific AChE activity was reduced in brain after treatments, no changes were observed in muscle tissue. Catalase activity in liver did not change during of exposure. Fish exposed to glyphosate demonstrated increased TBARS production in muscle tissue at both concentrations tested. For both glyphosate concentrations tested brain showed a reduction of TBARS after 96 h of exposure. The present results showed that in 96 h, glyphosate changed AChE activity, metabolic parameters and TBARS production. The parameters measured can be used as herbicide toxicity indicators considering environmentally relevant concentration.
Asunto(s)
Acetilcolinesterasa/efectos de los fármacos , Bagres/fisiología , Glicina/análogos & derivados , Herbicidas/toxicidad , Contaminantes Químicos del Agua/toxicidad , Acetilcolinesterasa/metabolismo , Amoníaco/metabolismo , Animales , Biomarcadores/metabolismo , Encéfalo/efectos de los fármacos , Encéfalo/enzimología , Relación Dosis-Respuesta a Droga , Monitoreo del Ambiente/métodos , Femenino , Glicina/toxicidad , Glucógeno/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Fibras Musculares de Contracción Rápida/enzimología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Proteínas/metabolismo , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Pruebas de Toxicidad Aguda , GlifosatoRESUMEN
We compared the sarcoplasmic reticulum (SR) Ca-ATPase from masseter (M) and medial pterygoid (MP) muscles with that from fast muscles (FM) to examine whether its calcium transport capability and enzymatic activity are different. SR vesicles from FM, M, and MP muscles were obtained according to Champeil et al.(1985). Assays for characterization of the enzyme properties were performed. The results showed similar optimal conditions for the Ca-ATPase activity and calcium transport in M, MP, and FM. However, the maximal values of calcium transport, Ca-ATPase activity, and K(i) for thapsigargin were significantly lower in the masticatory muscles. These findings are likely related to different Ca-ATPase isoforms. Since the local anesthetics used in dentistry inhibit Ca-ATPase and calcium transport in FM, it will be important for the effects of these drugs on the Ca-ATPase of masticatory muscles to be assessed.
Asunto(s)
ATPasas Transportadoras de Calcio/metabolismo , Músculos Masticadores/enzimología , Fibras Musculares de Contracción Rápida/enzimología , Proteínas Musculares/metabolismo , Retículo Sarcoplasmático/enzimología , Animales , ATPasas Transportadoras de Calcio/aislamiento & purificación , Masculino , Músculo Esquelético/enzimología , ConejosRESUMEN
The aim of this study was to investigate if the Na(+)-channel activating alkaloid veratrine is able to change the oxidative and m-ATPase activities of a fast-twitch glycolytic muscle (EDL, extensor digitorum longus) and slow-twitch oxidative muscle (SOL, soleus) in mice. Oxidative fibers and glycolytic fibers were more sensitive to veratrine than oxidative-glycolytic fibers 15, 30 and 60 min after the i.m. injection of veratrine (10 ng/kg) with both showing an increase in their metabolic activity in both muscles. In EDL, the m-ATPase reaction revealed a significant (p < 0.001) decrease (50%) in the number of type IIB fibers after 30 min while the number of type I fibers increased by 550%. Type I fibers decreased from 34% in control SOL to 17% (50% decrease) in veratrinized muscles, with a 10% decrease in type IIA fibers within 15 min. A third type of fiber appeared in SOL veratrinized muscle, which accounted for 28% of the fibers. Our work gives evidence that the changes in the percentage of the fiber types induced by veratrine may be the result, at least partially, from a direct effect of veratrine on muscle fibers and else from an interaction with the muscle type influencing distinctively the response of a same fiber type. Based on the results obtained in the present study the alterations in EDL may be related to the higher number of Na(+) channels present in this muscle whereas those in SOL may involve an action of veratrine on mitochondria. Although it is unlikely that the shift of enzymes activities induced by veratrine involves genotypic expression changes an alternative explanation for the findings cannot be substantiated by the present experimental approach.
Asunto(s)
Fibras Musculares de Contracción Rápida/efectos de los fármacos , Fibras Musculares de Contracción Lenta/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Veratrina/farmacología , Adenosina Trifosfatasas/análisis , Adenosina Trifosfatasas/metabolismo , Animales , Histocitoquímica , Inyecciones Intramusculares , Masculino , Ratones , Ratones Endogámicos BALB C , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/patología , Fibras Musculares de Contracción Lenta/enzimología , Fibras Musculares de Contracción Lenta/patología , Músculo Esquelético/enzimología , Músculo Esquelético/patología , Miosinas/análisis , Miosinas/metabolismo , Isoformas de Proteínas , Canales de Sodio/metabolismo , Veratrina/administración & dosificaciónRESUMEN
Samples of the anterior and posterior regions of the masseter and temporal muscles and of the anterior belly of the digastric muscle of 4 adult male tufted capuchin monkeys (Cebus apella) were removed and stained with HE and submitted to the m-ATPase reaction (with alkaline and acid preincubation) and to the NADH-TR and SDH reactions. The results of the histoenzymologic reactions were similar, except for acid reversal which did not occur in fibers of the fast glycolytic (FG) type in the mandibular locomotor muscles. FG fibers had a larger area and were more frequent in all regions studied. No significant differences in frequency or area of each fiber type were detected, considering the anterior and posterior regions of the masseter and temporal muscles. The frequency of fibers of the fast oxidative glycolytic (FOG) and slow oxidative (SO) types and of FOG area differed significantly between the anterior belly of the digastric muscle and the mandibular locomotor muscle. The predominance of fast twitch (FG and FOG) fibers and the multipenniform and bipenniform internal architecture of the masseter and temporal muscles, respectively, are characteristics that permit the powerful bite typical of tufted capuchin monkeys.
Asunto(s)
Adenosina Trifosfatasas/metabolismo , Cebus/fisiología , Músculos Masticadores/anatomía & histología , Músculos Masticadores/enzimología , NADH Tetrazolio Reductasa/metabolismo , Succinato Deshidrogenasa/metabolismo , Animales , Biopsia , Masculino , Fibras Musculares de Contracción Rápida/citología , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Lenta/citología , Fibras Musculares de Contracción Lenta/enzimologíaRESUMEN
The purpose of the present work was to study some morphological differences of similar muscle fiber types--classified by ATPase reactions in different muscles of rats. Morphological parameters were used as stereological techniques at light and electron microscopic level. There was a great variation in the diameter of each muscle fiber type of different muscles. The smallest diameter of type 1 myofibers of the soleus was greater than the diameter of type 1 myofibers of other muscles. The diameter of type 1 myofibers of the soleus and of the lateral part of the gastrocnemius was almost twice the diameter of type 1 myofibers of sternocleidomastoid. The lateral and medial parts of gastrocnemius had the largest 2A and 2B muscle fibers. As a whole, among the studied muscles, myofibers of postural muscles of the posterior parts of the posterior limbs had the greatest diameter. Stereological analysis at electron microscopic level revealed that there were differences in the volume density of mitochondria in the different muscles. The quantity of mitochondria was greater in the diaphragm than in the gastrocnemius, soleus and sternocleidomastoid muscles. Our results suggested that the diameter of muscle fibers is more related to the resistance the muscle is submitted than to the continuous necessity of contraction. However, the quantity of mitochondria of oxidative fibers of the diaphragm would be related to continuous necessity of contraction and high oxidative necessity of this muscle.
Asunto(s)
Fibras Musculares de Contracción Rápida/ultraestructura , Fibras Musculares de Contracción Lenta/ultraestructura , Músculo Esquelético/ultraestructura , Adenosina Trifosfatasas/metabolismo , Animales , Histocitoquímica , Mitocondrias/ultraestructura , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Lenta/enzimología , Músculo Esquelético/enzimología , Ratas , Ratas WistarRESUMEN
The aim of this study was to determine if there is a relationship among skeletal muscle fiber composition, capillarization, blood pressure (BP) and/or the components of the metabolic syndrome. Two groups were compared: 8 recently diagnosed, untreated, hypertensive men (BP > or = 140/90) and 7 normotensive men as controls. Muscle biopsies were taken from the vastus lateralis part of quadriceps femoris muscle in order to assess: fiber type proportion, capillarization, hexokinase, citrate synthase, beta-hydroxyacyl CoA dehydrogenase activities; lipoprotein lipase mass and activity, free fatty acids and triglycerides. Serum levels of insulin, glucose, cholesterol, uric acid and triglycerides were also assayed. Hypertensive patients had higher insulin levels and insulin resistance [homeostasis model assessment (HOMA)], a decreased hexokinase activity and an increase of muscle lipoprotein lipase mass as compared to controls. Interestingly, correlations among values differ in each group. The percentage of type IIB fibers was related to diastolic BP (blood pressure) in control and to mean BP in hypertensive subjects. Serum cholesterol and glucose were inversely related to the percentage of type I fibers in the control subjects. Negative correlations between capillarization and glucose, cholesterol and uric acid levels were found in control subjects. In all subjects, a strong correlation was found between SBP (systolic BP) and DBP (diastolic BP), and insulin resistance (IR) and uric acid levels. Muscle fiber type proportion and capillarization were related to blood pressure and components of the metabolic syndrome.
Asunto(s)
Hipertensión/enzimología , Hipertensión/patología , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Lenta/enzimología , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/enzimología , Adulto , Presión Sanguínea , Capilares/patología , Diástole , Humanos , Hipertensión/fisiopatología , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Sístole , MusloRESUMEN
The effects of veratrine have been investigated in mammalian, amphibian, and crustacean muscle, but not in fish. In this work, the action of veratrine was studied in the lateral muscle of the freshwater teleost Oreochromis niloticus after intramuscular injection. Histoenzymological typing and electron microscopy of muscle fibers before and 15, 30, and 60 min after veratrine injection (10 ng/kg fish) were used to indirectly assess the morphological changes and the oxidative and m-ATPase activities. In some cases, muscles were pretreated with tetrodotoxin to determine whether the ultrastructural changes were the result of Na(+) channel activation by veratrine. Veratrine altered the metabolism of fibers mainly after 30 min. Oxidative fibers showed decreased NADH-TR activity, whereas that of glycolytic and oxidative-glycolytic type fibers increased. There was no change in the m-ATPase activity of the three fiber types, except at 60 min postveratrine, when a novel fiber type, which showed no reversal after acidic and alkaline preincubations, appeared. Ultrastructural damage involved sarcomeres, myofibrils, and mitochondria, but the T-tubules remained intact. Pretreatment with tetrodotoxin (1 ng/ml) prevented the ultrastructural changes caused by veratrine. These results show that in fish skeletal muscle veratrine produces some effects that are not seen in mammalian muscle.
Asunto(s)
Cíclidos , Músculo Esquelético/efectos de los fármacos , Veratrina/toxicidad , Adenosina Trifosfatasas/metabolismo , Antagonismo de Drogas , Inyecciones Intramusculares , Microscopía Electrónica , Mitocondrias Musculares/efectos de los fármacos , Mitocondrias Musculares/ultraestructura , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Fibras Musculares de Contracción Rápida/enzimología , Fibras Musculares de Contracción Rápida/ultraestructura , Fibras Musculares de Contracción Lenta/efectos de los fármacos , Fibras Musculares de Contracción Lenta/enzimología , Fibras Musculares de Contracción Lenta/ultraestructura , Músculo Esquelético/enzimología , Músculo Esquelético/ultraestructura , Sarcómeros/efectos de los fármacos , Sarcómeros/ultraestructura , Tetrodotoxina/toxicidad , Veratrina/administración & dosificaciónRESUMEN
Astronotus ocellatus is one of the most hypoxia tolerant fish of the Amazon; adult animals can tolerate up to 6 h of anoxia at 28 degrees C. Changes in energy metabolism during growth have been reported in many fish species and may reflect the way organisms deal with environmental constraints. We have analyzed enzyme levels (lactate dehydrogenase, LDH: EC 1.1.1.27; and malate dehydrogenase, MDH: EC 1.1.1.37) in four different tissues (white muscle, heart, liver, and brain) from different-sized animals. Both enzymes correlate with body size, increasing the anaerobic potential positively with growth. To our knowledge, this is the first description of scaling effects on hypoxia tolerance and it is interesting to explore the fact that hypoxia survivorship increases due to combining effects of suppressing metabolic rates and increasing anaerobic power as fish grow.
Asunto(s)
L-Lactato Deshidrogenasa/metabolismo , Malato Deshidrogenasa/metabolismo , Oxígeno/fisiología , Percas/fisiología , Animales , Peso Corporal , Encéfalo/enzimología , Hígado/enzimología , Fibras Musculares de Contracción Rápida/enzimología , Miocardio/enzimología , Estaciones del Año , Estadística como Asunto , Extractos de TejidosRESUMEN
The sarcoplasmic reticulum Ca2+-ATPase (calcium-dependent adenosine triphosphatase) transports Ca2+ from the myoplasm to the reticulum lumen at the expense of free energy from ATP hydrolysis. Carticaine is a local anesthetic of frequent use in dentistry which is now entering other clinical fields. We studied the action of carticaine on the sarcoplasmic reticulum (SR) skeletal muscle Ca2+-ATPase. SR vesicles from rabbit fast skeletal muscle were used. Carticaine inhibits the enzymatic activity. The inhibition of the enzymatic activity depends on pH, [Ca2+] and the presence of calcimycin. Half-maximal carticaine concentration that inhibits the ATPase activity tends to a maximal value upon increasing [Ca2+]. Carticaine concentrations required to inhibit the enzymatic activity at myoplasmic calcium concentration are lower than usual clinical doses: Ki=6.0+/-1.4 mM carticaine (n=5) for 0.1 microM [Ca2+]. ATP-dependent calcium uptake is also inhibited by the local anesthetic: Ki=30.5+/-3.4 mM (n=4). Besides, carticaine inhibits the phosphorylation of the enzyme by inorganic phosphate (Pi): Ki=20.0+/-3.4 (n=5) - 33.2+/-4.6 (n=4) mM, for [Pi] 1-4 mM. Carticaine increases the membrane permeability to Ca2+. Ca2+ efflux from preloaded vesicles is prevented by Ca2+ and Mg2+. Our results suggest that the diffusion of the local anesthetic into muscle fibers might trigger undesired effects such as sustained contraction of the masticatory muscles.
Asunto(s)
Anestésicos Locales/farmacología , ATPasas Transportadoras de Calcio/antagonistas & inhibidores , Carticaína/farmacología , Animales , Calcimicina/farmacología , Calcio/metabolismo , Calcio/farmacología , ATPasas Transportadoras de Calcio/metabolismo , Ionóforos/farmacología , Cinética , Magnesio/farmacología , Fibras Musculares de Contracción Rápida/efectos de los fármacos , Fibras Musculares de Contracción Rápida/enzimología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/enzimología , Fosfatos/metabolismo , Fosfatos/farmacología , Fosforilación/efectos de los fármacos , Conejos , ATPasas Transportadoras de Calcio del Retículo SarcoplásmicoRESUMEN
Arterial hypertension produces changes along the vascular tree. However, there are few reports on its effect on human muscle capillaries. This study demonstrates the effects of essential hypertension on the capillaries of human quadriceps muscle. Muscle biopsy was taken from quadriceps femoris in eight men with recent diagnosis of essential hypertension, without treatment. Biopsies were also taken from eight normotensive men and were used as controls. Fiber types were classified by ATPase reaction, capillaries counted in alpha-amylase-PAS stained sections and ultrastructure studied by conventional methods of transmission electron microscopy. No changes were found in capillaries or muscle fiber types by histochemical methods. However, electron microscopy revealed abnormal capillaries with endothelial cells infoldings into the lumen, as well as occluded or degenerated capillaries. In some cases the endothelial cell area covered by pericytes was increased. Basement membrane of capillaries was frequently increased in width, sometimes irregularly, and in other instances it was reduplicated. In transversely sectioned capillaries lumen diameter was reduced and wall thickness was increased, although total diameter was unchanged. In hypertensive patients the finding of some degenerated capillaries adjacent to muscle fibers could be interpreted as the beginning of a process of rarefaction. Some capillaries showed morphological changes, and the ratio wall thickness/lumen was increased.