Search results for "Muscles"
showing 10 items of 616 documents
Muscle enzyme adaptations to added load during training and nontraining hours in rats.
1991
The effects of added load (20% of body mass) on the selected enzyme activities of red and white quadriceps femoris (QF), soleus, and gastrocnemius muscles of rats were studied. The rats were divided into sedentary control (SC), sedentary control with added load (SC+AL), endurance training (ET), and endurance training with added load (ET+AL) groups (n = 10 rats/group). After 6 wk, the SC+AL group had 57% higher (P less than 0.001) beta-glucuronidase (beta-GU) activity and 24% lower (P less than 0.05) citrate synthase activity in white QF than SC. Citrate synthase activity was also decreased in red QF (P less than 0.05) after the added load was used during nontraining hours. The training wit…
Connective tissue of “fast” and “slow” skeletal muscle in rats…effects of endurance training
1980
The connective tissue of two skeletal muscles having different contractile properties was investigated in trained and untrained rats. The animals to be trained were put to run on a treadmill 5 days a week for 4 weeks. The "slow" m. soleus (MS) showed higher malate dehydrogenase activity but lower lactate dehydrogenase activity compared to the "fast" m. rectus femoris (MRF). When whole muscles were taken into account, the concentrations of both hydroxyproline and hexosamines were higher for MS compared to MRF. In the middle section of MS there were more hexosamines than in that of MRF, but no similar difference existed in hydroxyproline. The histochemical staining of collagen, however, sugge…
Aerobic performance capacity in athletes
1978
Maximal oxygen uptake (max\(\dot V\)O2) in leg and arm work, succinate dehydrogenase activity (SDH) and percentage of slow twitch fibers (%ST fibers) in M. vastus lateralis (VL), M. gastrocnemius c.l. (GL) and M. deltoideus (D) were studied in 89 athletes practising 11 different sport events. It was found that maximal oxygen uptake correlated positively with %ST fibers and SDH activity in M. VL. The SDH activity and %ST fibers in M. VL correlated also with one another. The results suggest that oxidative capacity of the muscles is not the limiting factor for maximal oxygen uptake. The role of the oxidative capacity of the muscles might be important during submaximal work of long duration and…
Peripheral benzodiazepine binding sites on striated muscles of the rat: Properties and effect of denervation
1985
In order to test the hypothesis that peripheral benzodiazepine binding sites mediate some direct effects of benzodiazepines on striated muscles, the properties of specific 3H-Ro 5-4864 binding to rat biceps and rat diaphragm homogenates were investigated. In both tissues a single population of sites was found with a KD value of 3 nmol/l. The density of these sites in both muscles was higher than the density in rat brain, but was considerably lower than in rat kidney. Competition experiments indicate a substrate specificity of specific 3H-Ro 5-4864 binding similar to the properties already demonstrated for the specific binding of this ligand to peripheral benzodiazepine binding sites in many…
Effects of endurance training on alkaline protease activities in rat skeletal muscles.
1983
This study aimed at comparing the effects of running and swimming training protocols and the termination of training on the activities of two proteases with alkaline pH-optima (alkaline protease and myofibrillar protease) in the tibialis anterior, soleus, and gastrocnemius muscles of male rats. The training on treadmill decreased the activities of alkaline and myofibrillar proteases by approx. 10-20% in the muscles studied. The activities of both proteases were unchanged in swimming-trained rats. Two weeks after the termination of running training the activity of alkaline protease was increased in gastrocnemius muscle but not in the other muscles. Swimming training increased the activity of…
Mitochondrial myopathy with lactic acidosis and deficient activity of muscle succinate cytochrome-c-oxidoreductase
1984
A male infant had severe muscular hypotonia from birth. Recurrent vomiting with dehydration and severe metabolic acidosis complicated the course. Elevated lactate (up to 12.3 mmol/l; n less than 2), pyruvate (0.4 mmol/l; n less than 0.05) and alanine levels were found in serum with an abnormal lactate/pyruvate ratio (greater than 30; n less than 15). In urine the concentrations of lactate, pyruvate, alanine and of several intermediates of the citric acid cycle were increased. In muscle, numerous disseminated "ragged red fibres" were found by light microscopy; muscle fibres were found to contain subsarcolemmal aggregates of mitochondria, lipid droplets and glycogen by electromicroscopical me…
Mitochondrial myopathy--a result of clofibrate/etofibrate treatment? Case report.
1985
A 66-year-old man had developed a myopathy while undergoing several periods of etofibrate and clofibrate therapy over the past 5 years. Discontinuation of etofibrate treatment failed to reverse his muscle illness which, however, did not progress. A muscle biopsy revealed a chronic myopathy marked by abundant, abnormally structured muscle mitochondria. His mitochondrial myopathy may represent a forme fruste of the Kearns-Sayre syndrome or other types of mitochondrial myopathy, clinically made evident by the etofibrate/clofibrate therapy, or a permanent, adverse side effect of clofibrate treatment. If the latter assumption proves to be correct, it will indicate that clofibrate therapy may ind…
Dose–volume-related dysphagia after constrictor muscles definition in head and neck cancer intensity-modulated radiation treatment
2014
Dysphagia remains a side effect influencing the quality of life of patients with head and neck cancer (HNC) after radiotherapy. We evaluated the relationship between planned dose involvement and acute and late dysphagia in patients with HNC treated with intensity-modulated radiation therapy (IMRT), after a recontouring of constrictor muscles (PCs) and the cricopharyngeal muscle (CM).Between December 2011 and December 2013, 56 patients with histologically proven HNC were treated with IMRT or volumetric-modulated arc therapy. The PCs and CM were recontoured. Correlations between acute and late toxicity and dosimetric parameters were evaluated. End points were analysed using univariate logisti…
Morphological and biochemical changes in striated muscle after experimental tourniquet ischaemia.
1979
Histological and biochemical changes were studied in the striated muscle following total tourniquet ischaemia between one and four h, the reflow time being 30 min and 24 h. Electronmicroscopy was applied to study the fine structure of the muscle after 24 h reflow. In light microscopy ischaemic changes were not seen even when the tourniquet time was extended to four h. When a four-h ischaemia was followed by a 24-h recovery period, the electron microscopy showed a variety of minor mitochondrial changes such as condensed and slightly dilatated mitochondria. The SDH activities did not vary significantly between the experimental and control samples even after a four-h ischaemia followed by 30 m…
Acid hydrolase activity in red and white skeletal muscle of mice during a two-week period following exhausting exercise
1978
The activities of beta-glucuronidase, beta-N-acetylglucosaminidase, arylsulphatase, ribonuclease, p-nitrophenylphosphatase, and malate dehydrogenase together with protein content were assayed from representative mixed (m. rectus femoris), predominantly red (proximal heads of m. vastus lateralis, m.v. medius and m. v. intermedius), and predominantly white (distal head of m. vastus lateralis) muscle homogenates of mice during a two-week period following one single exposure to exhausting intermittent running on a treadmill. The activities of cathepsin D and beta-glycerophosphatase were assayed from mixed muscle only. In all three muscle types, particularly in red muscle, the activities of beta…