Search results for "skeletal muscle"

Collagen of slow twitch and fast twitch muscle fibres in different types of rat skeletal muscle

1984

The appearance of collagen around individual fast twitch (FT) and slow twitch (ST) muscle fibres was investigated in skeletal muscles with different contractile properties using endurance trained and untrained rats as experimental animals. The collagenous connective tissue was analyzed by measuring hydroxyproline biochemically and by staining collagenous material histochemically in M. soleus (MS), M. rectus femoris (MRF), and M. gastrocnemius (MG). The concentration of hydroxyproline in the ST fibres dissected from MS (2.72 +/- 0.35 micrograms X mg-1 d.w.) was significantly higher than that of the FT fibres dissected from MRF (1.52 +/- 0.33 micrograms X mg-1 d.w.). Similarly, the concentrat…

Initial inflammatory response of skeletal muscle to commonly used suture materials: An animal model study to evaluate muscle healing after surgical r…

2013

Objectives: To evaluate initial inflammatory response of skeletal muscle to a few commonly used suture materials for muscle repair namely nylon, polydiaxonone (PDS II), plain catgut and polygalactin 910 which in turn determines the scarring of muscle and loss of function. Material and Methods: Inflammation and healing of muscle post repair was evaluated in the lateral thigh muscle (biceps femoris) of 8 adult healthy male Rattus norvegicus. The inflammatory reaction & healing of the skeletal muscle was evaluated histologically at the end of 48 hours, 1 week and 3 weeks. Results: At 48 hours post-surgery, Nylon samples showed severe inflammation followed by Catgut and Polygalactin. At 1 week …

Some glutathione-related enzymic activities in skeletal muscle and myocardium of the rat : adaptations to endurance training

1991

Oxidative and lysosomal capacity in skeletal muscle of mice after endurance training of different intensities

1978

The activity of certain enzymes of energy metabolism (cytochrome c oxidase, citrate synthase, malate dehydrogenase, and lactate dehydrogenase) and of lysosomes (beta-glucuronidase, beta-N-acetylglucosamindase, arylsuphatase, ribonuclease, deoxyribonuclease, acid phosphatase, and cathepsin D) was assayed from m. rectus femoris of mice trained 5 days per week, 1 hr per day for 4 weeks according to 4 different programmes: I. running speed 20 m/min, horizontal track, II. 25 m/min, horizontal track, III. 20 m/min 8 degrees uphill inclination, and IV. 25 m/min 8 degrees uphill inclination. Oxidative capacity increased and anaerobic capacity decreased without distinction between the different tran…

?-Glucuronidase activity in trained red and white skeletal muscle of mice

1978

We studied the effects of prolonged running exercise (5 days a week, 1.5 h per day at a speed of 17.6 m/min) on the activity of some acid hydrolases (beta-glucuronidase, beta-N-acetylglucosaminidase, acid phosphatase and cathepsin D) and three enzymes of energy metabolism (cytochrome c oxidase, lactate dehydrogenase and creatine kinase) in the distal and in the proximal, the predominantly white and red parts, respectively, of the vastus lateralis-muscle from mice. The acid hydrolase activity levels were 1.24--1.69 higher in untrained red muscle compared to untrained white muscle. The light training applied increased the activity of beta-glucuronidase in both red and white muscle. No other s…

Effects of physical training on metabolism of connective tissues in young mice.

1980

The effects of physical training on the metabolism of collagen, calcium and glycosaminoglycans in various connective tissues were studied in male NMRI mice. The mice to be trained and their controls were about 3 weeks old (expt. I) and 8 weeks old (expt. II) at the commencement of training. The training was performed on a 5 degree inclined treadmill 5 days a week for 4 weeks in expt. I and for 3 weeks in expt. II. The daily exercise time was progressively increased from 20 min in the first week up to 80 min in the third week. The incorporation of 3H-proline to collagen hydroxyproline was increased by training in long bones, skeletal muscle and Achilles tendon, whereas the incorporation of 3…

Muscle protein synthesis, mTORC1/MAPK/Hippo signaling, and capillary density are altered by blocking of myostatin and activins

2012

Loss of muscle mass and function occurs in various diseases. Myostatin blocking can attenuate muscle loss, but downstream signaling is not well known. Therefore, to elucidate associated signaling pathways, we used the soluble activin receptor IIb (sActRIIB-Fc) to block myostatin and activins in mice. Within 2 wk, the treatment rapidly increased muscle size as expected but decreased capillary density per area. sActRIIB-Fc increased muscle protein synthesis 1–2 days after the treatment correlating with enhanced mTORC1 signaling (phosphorylated rpS6 and S6K1, r = 0.8). Concurrently, increased REDD1 and eIF2Bε protein contents and phosphorylation of 4E-BP1 and AMPK was observed. In contrast, pr…

Cannabinoid receptor 1 and acute resistance exercise – In vivo and in vitro studies in human skeletal muscle

2015

Abstract Aim This study aimed to determine whether Cannabinoid receptor 1 (CB1) is involved in mammalian target of rapamycin (mTOR) signaling and skeletal muscle protein synthesis. Methods This study used human vastus lateralis skeletal muscle biopsies obtained before and after a resistance exercise (RE) bout in young men (n = 18). The signaling mechanisms were studied in vitro in human myotubes. Protein expression was determined by Western blot and confocal microscopy, and gene expression by quantitative PCR. Protein synthesis was measured in vitro using puromycin-based SuNSET technique. Results In human skeletal muscle, an anabolic stimulus in the form of RE down-regulated CB1 expression.…

Control of glycolysis in vertebrate skeletal muscle during exercise

1996

The gastrocnemius muscle of the frog (Rana temporaria) has a high capacity for anaerobic glycolysis from glycogen. Glycolytic metabolites and effectors of phosphofructokinase, particularly the hexose bisphosphates, were followed in muscle during exercise (swimming between 5 s and 5 min), recovery (rest for up to 2 h after 5 min of swimming), and repeated exercise (swimming for up to 60 s after 2 h of recovery). Glycogen phosphorylase and phosphofructokinase were swiftly activated with exercise. The hexose bisphosphates followed markedly different time courses. Fructose 1,6-bisphosphate was transiently increased in both exercise and repeated exercise. This appears to be an effect rather tha…

Food deprivation decreases the exertion-induced acid hydrolase response in mouse skeletal muscle

1988

Strenuous prolonged running causes muscle fibre necrosis in skeletal muscles. The muscle injury is associated with inflammation and a strong increase in the total activities of certain acid hydrolases a few days after exertion. The activity changes of acid hydrolases quantitatively well reflect the severity of histopathological changes during the myopathy (for review see Salminen, Acta Physiol Scand [Suppl 539] 1985). In this study male NMRI-mice were exposed to a protocol of fasting and refeeding together with or without a 6 h run on a treadmill at 13.5 m.min-1. The animals were killed 4 days after the exercise and samples from the red part of quadriceps femoris were analyzed for arylsulfa…