Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Favourable associations between the myosin heavy-chain and light-chain isoforms in human skeletal muscle (1990)
    Springer
    Pflügers Archiv 416 (1990), S. 689-693 
    Details
    ISSN: 1432-2013
    Keywords: Skeletal muscle ; Myosin light chain ; Myosin heavy chain ; Fibre type ; Isoforms ; Percentage fibre type area ; Favourable association
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Histochemical and biochemical analyses were performed in order to examine the relationship between myosin light-chain (LC) isoforms and fibre-type distributions in whole human skeletal muscle. Muscle biopsies were obtained from the vastus lateralis muscle in six healthy men, and analysed for the relative area occupied by each fibre type (percentage of fibre type area) and the molar ratio of each LC isoform. The percentage of type I fibre area was positively correlated with the molar ratio of slow LC (LC1s and LC2s) to total LC. The regression line was located below the line of unity. Also, the ratio of percentage of type II fibre area to that of type II fibre area was positively correlated with the molar ratio of the fast alkali LC LC1f to fast alkali LCs LC1f and LC3f. These results support previous study, having shown that in human skeletal muscle some type I fibres express various amounts of fast LC in addition to slow LC and suggest that fast myosin heavy-chain HCII a is favourably associated with LC1f, whereas HCIIb is favourably associated with LC3f.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00370616
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Muscle energetics in short-term training during hypoxia in elite combination skiers (1994)
    Springer
    European journal of applied physiology 69 (1994), S. 301-304 
    Details
    ISSN: 1439-6327
    Keywords: Skiers ; Muscle energetics ; Hypoxia ; Phosphocreatine ; Intracellular pH
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Four well-trained combination skiers were studied through pre- and post-training for the effects of short-term intermittent training during hypoxia on muscle energetics during submaximal exercise as measured by Phosphorus-31 nuclear magnetic resonance and maximal aerobic power ( $$\dot V$$ O2max). The hypoxia and training in the cold was conducted in a hypobaric chamber and comprised 60-min aerobic exercise (at an intensity equivalent to the blood lactate threshold), using a cycle ergometer or a treadmill twice a day for 4, consecutive days at 5°C, in conditions equivalent to an altitude of 2000 m (593 mm Hg). No change in $$\dot V$$ O2max was observed over the training period, while in the muscle energetics during submaximal exercise, the values of phosphocreatine/(phosphocreatine + inorganic phosphate) and intracellular pH were found to be significantly increased by training during hypoxia. During recovery, the time constant of phosphocreatine was found to have been significantly reduced [pre, 27.9 (SD 6.7) s; post, 22.5 (SD 4.7) s, P 〈 0.01]. The observed inhibition of phosphocreatine as well as that of intracellular pH changes after training during hypoxia and quicker recovery of phosphocreatine in submaximal exercise tests, may indicate improved oxidative capacity (i.e. a high adenosine 5′-triphosphate formation rate) despite the short-term hypoxia training.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00392034
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Changes in magnetic resonance images in human skeletal muscle after eccentric exercise (1994)
    Springer
    European journal of applied physiology 69 (1994), S. 408-413 
    Details
    ISSN: 1439-6327
    Keywords: Magnetic resonance imaging ; Muscle soreness ; Eccentric exercise ; Relaxation time ; Muscle cross-sectional area
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To investigate the time-course of changes in transverse relaxation time (T2) and cross-sectional area (CSA) of the quadriceps muscle after a single session of eccentric exercise, magnetic resonance imaging was performed on six healthy male volunteers before and at 0, 7, 15, 20, 30 and 60 min and 12, 24, 36, 48, 72 and 168 h after exercise. Although there was almost no muscle soreness immediately after exercise, it started to increase 1 day after, peaking 1–2 days after the exercise (P〈0.01). Immediately after exercise, T2 increased significantly in the rectus femoris, vastus lateralis and intermedius muscles (P〈0.05) and decreased quickly continuing until 60 min after exercise. At and after the 12th h, a significant increase was perceived again in the T2 values of the vastus lateralis and intermedius muscles (P〈0.01) [maximum 9.3 (SEM 2.8)% and 10.9 (SEM 2.2)%, respectively]. The maximal values were exhibited at 24–36 h after exercise. In contrast, the rectus femoris muscle showed no delayed-stage increase. Also, in CSA, an increase after 12 h was observed in addition to the one immediately after exercise in the vastus lateralis, intermedius and medialis and quadriceps muscles as a whole (P 〈 0.01), reaching the maximal values at 12–24 h after exercise. The plasma creative kinase activity remained unchanged up to 24 h after and then increased significantly 48 h after exercise (P 〈 0.05). Beginning 12 h after exercise, the subjects whose T2 and CSA increased less than the others displayed a faster decrease in muscle soreness. These results suggested that T2 and CSA displayed bimodal responses after eccentric exercise and the time-courses of changes in them were similar to those in muscle soreness.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00865404
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Phosphorus-31 nuclear magnetic resonance study on the effects of endurance training in rat skeletal muscle (1992)
    Springer
    European journal of applied physiology 65 (1992), S. 197-201 
    Details
    ISSN: 1439-6327
    Keywords: Phosphorus-31 nuclear magnetic resonance ; Muscle metabolism ; Phosphocreatine ; Adenosine 5′-triphosphate ; Endurance training ; Muscle fibre type
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To evaluate changes in muscle energetics following endurance training, we measured phosphorus-31 nuclear magnetic resonance (31P NMR) spectra on rat muscle in vivo before and after training in the same animals. The endurance training lasted for 3 months. The31P NMR spectra were obtained serially at rest, during exercise by electrical stimulation, and during recovery. Intramuscular phosphocreatine (PCr), inorganic phosphate (Pi, adenosine 5′-triphosphate (ATP) and pH were determined from the NMR spectra. The ratio of PCr : (PCr + Pi) at rest showed no difference between the trained and control groups even after 3 months of training. During exercise, however, this ratio was significantly higher in the trained group than in the control group. The ratio also recovered more rapidly after exercise in the trained group. The intramuscular pH decreased slightly by approximately 0.1 pH unit during exercise but did not show a significant difference between the groups. These results indicated that endurance training of 3 months duration improved the ATP supply system in the muscle. They also demonstrated that31P NMR is a potent method for evaluating the effects of training in the same individuals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00705081
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Measurement of muscle fibre displacement during contraction by real-time ultrasonography in humans (1995)
    Springer
    European journal of applied physiology 70 (1995), S. 45-48 
    Details
    ISSN: 1439-6327
    Keywords: Muscle fibre ; Ultrasonography ; Muscle contraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The contact point (P) made by both the echoes of the aponeurosis and from interspaces among fascicles of the tibialis anterior muscle was detected by real-time ultrasound scanning in 12 adults. Movement in the location of P was observed during muscle contraction and its displacement was related to changes in ankle joint angles (r = 0.81,P 〈 0.01), i.e. P shifted proximally when the ankle joint was dorsiflexed. There was also a significant positive correlation between the degree of dorsiflexion and the velocity related to the change in location of P (r = 0.84,P 〈 0.01). Ultrasound measurements of the displacement and the velocity of P were reproducible as there was no variation noticed among measurements on different days. It is suggested from these results that the displacement of P reflected changes in muscle length during contraction and that this amount of change corresponded to changes in joint angles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00601807
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Training-induced changes in muscle architecture and specific tension (1995)
    Springer
    European journal of applied physiology 72 (1995), S. 37-43 
    Details
    ISSN: 1439-6327
    Keywords: Muscle hypertrophy ; Pennation angle ; Physiological cross-sectional area
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Five men underwent unilateral resistance training of elbow extensor (triceps brachii) muscles for 16 weeks. Before and after training, muscle layer thickness and fascicle angles of the long head of the triceps muscle were measured in vivo using B-mode ultrasound, and fascicle lengths were estimated. Series anatomical cross-sectional areas (ACSA) of the triceps brachii muscle were measured by magnetic resonance imaging, from which muscle volume (Vm) was determined and physiological cross-sectional area (PCSA) was calculated. Elbow extension strength (isometric; concentric and eccentric at 30, 90 and 180°·s−1) was measured using an isokinetic dynamometer to determine specific tension. Muscle volumes, ACSA, PCSA, muscle layer thickness and fascicle angles increased after training and their relative changes were similar, while muscle and fascicle length did not change. Muscle strength increased at all velocities; however, specific tension decreased after training. Increase in fascicle angles, which would be the result of increasedV m and PCSA, would seem to imply the occurrence of changes in muscle architecture. This might have given a negative effect on the force-generating properties of the muscles.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00964112
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    The use of magnetic resonance images to investigate the influence of recruitment on the relationship between torque and cross-sectional area in human muscle (2000)
    Springer
    European journal of applied physiology 83 (2000), S. 475-480 
    Details
    ISSN: 1439-6327
    Keywords: Key words Human ; Muscle function ; Physiological cross-sectional area ; Magnetic resonance imaging
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The purpose of the present study was to investigate the effect of recruitment on the relationship between peak torque and physiological cross-sectional area (PCSA) in human muscle. A group of 11 healthy men participated in this study. Isokinetic knee extension torques at seven (0, 30, 60, 120, 180, 240, and 300° · s−1) velocities were determined. Magnetic resonance imaging (MRI) was performed to calculate PCSA of right quadriceps femoris (QF) muscle. Exercise-induced contrast shifts in spin-spin relaxation time (T2)-weighted MRI were taken at rest and immediately after repetitive knee-extension exercise and T2 of QF were calculated. The MRI pixels with T2 values more than 1 SD greater than the means at rest were considered to represent QF muscle that had contracted. The area of activated PCSA within the total in QF was expressed as percentage activated PCSA and used as an index of muscle recruitment. The PCSA correlated with peak torque at 0° · s−1 (r=0.615, P 〈 0.05); in contrast, activated PCSA correlated with peak torque at 120° · s−1 (r=0.603, P 〈 0.05) and 180° · s−1 (r=0.606, P 〈 0.05). Additionally, there was a significant difference in correlation coefficients between the activated PCSA-peak torque relationship and the PCSA-torque relationship (P 〈 0.05). These results suggested that muscle recruitment affects the PCSA-torque relationship.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004210000310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Muscle metabolism during exercise using phosphorus-31 nuclear magnetic resonance spectroscopy in adolescents (1995)
    Springer
    European journal of applied physiology 70 (1995), S. 301-304 
    Details
    ISSN: 1439-6327
    Keywords: Phosphorus-31 nuclear magnetic resonance ; Muscle metabolism ; Adolescent ; Anaerobic metabolism ; Glycolytic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Very little has been reported on muscle energetics during exercise in adolescents. This is attributable to the difficulty of subjecting children to muscle biopsy. The purpose of this study was to investigate the characteristics of muscle metabolism during exercisein vivo in adolescents by comparing firstly, with adults and secondly, the differences resulting from physical activity using phosphorus-31 nuclear magnetic resonance (31PNMR) spectroscopy. The subjects were boys aged 12 to 15 years, comprising 21 trained boys and 23 control boys, and 6 adults controls. The ratio of phosphocreatine (PCr):(PCr + Pi), where Pi is inorganic phosphate intracellular pH at exhaustion and the time constant of PCr during recovery were measured in all the subjects using31PNMR. Both groups of children showed higher values of PCr:(PCr + Pi) and intracellular pH at exhaustion than did the adult control group (P 〈 0.01 orP 〈 0.05). However, no significant differences were found between the trained boys and the control boys with respect to PCr:(PCr + Pi) and intracellular pH at exhaustion. On the other hand, we found the same values for PCr time constant in all groups. This result suggested no differences of the muscle oxidative capacity between children and adults. We concluded that the adolescents, aged 12 to 15 years in both the trained and control groups, had less glycolytic ability during exercise than the adults.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00865026
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Effect of strength training on the relationship between magnetic resonance relaxation time and muscle fibre composition (1990)
    Springer
    European journal of applied physiology 61 (1990), S. 33-36 
    Details
    ISSN: 1439-6327
    Keywords: Magnetic resonance imaging ; Relaxation time ; Muscle fibre composition ; Strength training
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of muscle hypertrophy on the relationship between magnetic resonance (MR) relaxation time and muscle fibre composition was investigated. Relaxation time and muscle fibre composition were measured in five subjects before and after a 20-week period of strength training. Muscle fibre composition in all subjects exhibited a significant shift to a predominance of fast-twitch (FT) fibres as a result of 20-week strength training (% area FT fibres: mean values from 49.8%, SD 17.9% to 57%, SD 5.6%; P〈0.05). Longitudinal relaxation time (T1) and transverse relaxation time (T2) were prolonged significantly after strength training (T1 mean values from 334.9 ms, SD 13.6 to 359.0 ms, SD 9.0, P〈0.001; T2 from 27.5 ms, SD 0.9 to 30.8 ms, SD 2.3, P〈0.05). A constant relationship was observed in changes caused by strength training in muscle fibre composition (% area FT) and relaxation time, with a high correlation obtained between both parameters. These results indicate that MR relaxation time can be used for non-invasive estimation of muscle fibre composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00236690
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    In vivo human myocardial metabolism during aerobic exercise by phosphorus-31 nuclear magnetic resonance spectroscopy (1994)
    Springer
    European journal of applied physiology 69 (1994), S. 488-491 
    Details
    ISSN: 1439-6327
    Keywords: Phosphorus-31 nuclear magnetic resonance ; Myocardial metabolism ; Exercise ; Phosophocreatine ; Adenosine 5′-triphosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A few studies have been made in vivo on human myocardial energy metabolism. Hence, no discussion has taken place on metabolism during exercise or of training effects on metabolism. We examined human myocardial energy metabolism at rest and during exercise, and also training effects on the metabolism by phosphorus-31 nuclear magnetic resonance (31P NMR)-spectroscopy. Six sedentary male students (Cont) and six male long distance runners (Tr) were the subjects. Energy metabolism data were obtained from myocardium during rest and exercise by the region selection method using 31P NMR. Rotation of the legs while riding a bicycle, which was fitted with an ergometer we had made ourselves for NMR, imposed given exercise intensities. The heart rate was measured in a stationary phase during exercise. Although the heart rate at rest in the Tr group was significantly lower [Tr, 52.5 (SD 3.1) beat · min−1; Cont, 67.1 (SD 2.9) beat · min−1], no significant difference was observed in myocardial energy metabolism using the 31P NMR method [Tr, phosphocreatine/β-adenosine 5′-triphosphate (PCr/β-ATP); 1.51 (SD 0.02); Cont, 1.51 (SD 0.01)]. When NMR measurements were investigated at two different intensities of exercise, heart rates in the Cont group were significantly higher by about 20 beat · min −1 than those in the Tr group at both exercise intensities, while no difference in energy metabolism was observed between the groups or between rest and exercise [Tr, 75.9 (SD 3.6), 88.3 (SD 3.7) beat · min−; PCr/β-ATP 1.51 (SD 0.03), 1.51 (SD 0.03); Cont, 95.9 (SD 2.4), 115.1 (SD 3.5) beat · min−1 PCr/β-ATP 1.51 (SD 0.01), 1.51 (SD 0.04)]. Thus, during submaximal exercise as employed in this study, it would seem that the high energy phosphate level normally observed during rest may still be maintained. From these results, the absence of change in the myocardial PCr: ATP ratio suggested that adenosine 5′-diphosphate was not the primary regular of the increased metabolism needed to meet the higher cardiac workload during aerobic exercise in either group.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239864
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...