Bengt Saltin’s research while affiliated with University of Copenhagen and other places

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Publications (175)


FIGURE 1 | TEM images showing the subcellular localization of skeletal muscle mitochondria. All images are from leg muscle (vastus lateralis). (A) Overview of a part of fiber showing the myofibrillar (Myo) space and subsarcolemmal (SS) space. (B) The typical localization of SS mitochondria (mit) in skeletal muscle, also showing a intramyocellular lipid (IMCL). (C) In the Myo space, intermyofibrillar mitochondria are wrapped around the myofibrils, mainly in the I-band and often connected to an adjacent mitochondrion through the A-band. There is less marked connection between neighboring mitochondria in the I-band. (D) Intermyofibrillar mitochondria in the I-band on each side of the Z-line, with the t-tubular system (t-system) and mitochondria intertwined. (E) Overview demonstrating the IMF mitochondria are mainly located in the I-band on each side of the z-line and often connected to an adjacent mitochondrion in the same sarcomere through the A-band. All the gray structures in the fiber are mitochondria with slightly visible inner cristae. Glycogen granules can be seen as black dots. Z, Z-line; A, A-band; IMCL, intramyocellular lipid; T-tubule, transverse tubular system. Scale bar: A, 10 µm; B,C, 1 µm; D, 0.5 µm; E, 1 µm. Original magnification: A, x1,600; B,C, x20,000; D, x50,000; E, x13,000.
FIGURE 2 | The relationships between the percentage of MHC-1 and 3-hydroxyacyl-CoA dehydrogenase activity (HAD, n = 10) (A); citrate synthase activity (CS, n = 9) (B); and relative capacity to oxidize fat (HAD/CS ratio) (C). The open circles depict data for the arms and the leg black squares for the legs. For the arm and leg combined, there was a significant correlation between the MHC-1 content and HAD activity (r 2 = 0.32, P = 0.011), as well as the HAD/CS ratio (r 2 = 0.27, P = 0.021).
FIGURE 3 | Mitochondria content and subcellular localization in distinct fiber types and at whole-muscle level of leg and arm muscles. There was a tendency (P = 0.095) toward a higher mitochondrial content in the intermyofibrillar (IMF) and subsarcolemmal (SS) regions, of arm muscle (open bars) compared with leg muscle (filled bars) (A). This tendency is also apparent when calculating total mitochondrial content (IMF + SS) (B). (C) Weighted mitochondrial volumes in the arm and leg muscle, estimated from a fiber type distribution of 57 and 37% MHC-I for the leg and arm (n = 9), respectively. These MHC weighted values of whole-muscle mitochondrial content in arm and leg muscles are similar. Values are means ± SE (n = 29-30 fibers from 10 subjects).
The Muscle Fiber Profiles, Mitochondrial Content, and Enzyme Activities of the Exceptionally Well-Trained Arm and Leg Muscles of Elite Cross-Country Skiers
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August 2018

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89 Citations

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As one of the most physically demanding sports in the Olympic Games, cross-country skiing poses considerable challenges with respect to both force generation and endurance during the combined upper- and lower-body effort of varying intensity and duration. The isoforms of myosin in skeletal muscle have long been considered not only to define the contractile properties, but also to determine metabolic capacities. The current investigation was designed to explore the relationship between these isoforms and metabolic profiles in the arms (triceps brachii) and legs (vastus lateralis) as well as the range of training responses in the muscle fibers of elite cross-country skiers with equally and exceptionally well-trained upper and lower bodies. The proportion of myosin heavy chain (MHC)-1 was higher in the leg (58 ± 2% [34–69%]) than arm (40 ± 3% [24–57%]), although the mitochondrial volume percentages [8.6 ± 1.6 (leg) and 9.0 ± 2.0 (arm)], and average number of capillaries per fiber [5.8 ± 0.8 (leg) and 6.3 ± 0.3 (arm)] were the same. In these comparable highly trained leg and arm muscles, the maximal citrate synthase (CS) activity was the same. Still, 3-hydroxy-acyl-CoA-dehydrogenase (HAD) capacity was 52% higher (P < 0.05) in the leg compared to arm muscles, suggesting a relatively higher capacity for lipid oxidation in leg muscle, which cannot be explained by the different fiber type distributions. For both limbs combined, HAD activity was correlated with the content of MHC-1 (r2 = 0.32, P = 0.011), whereas CS activity was not. Thus, in these highly trained cross-country skiers capillarization of and mitochondrial volume in type 2 fiber can be at least as high as in type 1 fibers, indicating a divergence between fiber type pattern and aerobic metabolic capacity. The considerable variability in oxidative metabolism with similar MHC profiles provides a new perspective on exercise training. Furthermore, the clear differences between equally well-trained arm and leg muscles regarding HAD activity cannot be explained by training status or MHC distribution, thereby indicating an intrinsic metabolic difference between the upper and lower body. Moreover, trained type 1 and type 2A muscle fibers exhibited similar aerobic capacity regardless of whether they were located in an arm or leg muscle.

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Figure 1. Transmission electron microscopy and point-counting of subcellular lipid droplets A, acquisition of electron micrographs was systematically randomized to cover the subsarcolemmal (SS), superficial myofibrillar (SMF) and central myofibrillar regions (CMF) of each longitudinally oriented fibre. The arrow indicates the sarcolemma. (original magnification ×600, scale bar: 20 µm). B, subcellular localisations of lipid droplets. The arrow indicates the sarcolemma. C, close-up view of point-counting of subsarcolemmal lipid droplet volume fraction with grid (size 135 nm) overlay. The open circles indicate intersections touching a lipid droplet. * , a subsarcolemmal lipid droplet; * * , an intermyofibrillar lipid droplet; Mi, mitochondria; Z, Z-line. (Original magnification ×10,000, scale bar: 1 µm.)
Figure 2. Baseline subcellular lipid droplet distributions in arm (m. triceps brachii) and leg (m. vastus lateralis) muscle fibres (n = 20 observations) A, subcellular lipid droplet volume fractions. * P < 0.0001 main limb effect in intermyofibrillar and subsarcolemmal regions; †P = 0.0002 main fibre type effect in intermyofibrillar region. B, subcellular lipid droplet size in diameter. * P < 0.001 main limb effect in type 2 fibres; †P = 0.007 main fibre type effect in leg muscle. C, subcellular lipid droplet numbers. * P < 0.0001 main limb effect in intermyofibrillar and subsarcolemmal regions; †P < 0.0001 main fibre type effect in intermyofibrillar region. Bars and lines represent medians with interquartile range (A and C), or means with 95% confidence intervals (B).
Figure 4. The relationship between the volume fraction of intermyofibrillar lipid droplets in arm (m. triceps brachii) skeletal muscle fibres before exercise (Pre) and the subsequent net decline in this parameter following 1 h cross-country skiing time trial The decline in the volume fraction of lipid droplets was positively associated with the corresponding volume at Pre. The open triangles represent type I fibres (n = 10 observations), and open circles type II fibres (n = 10 observations). The line was fitted linearly.
Pronounced limb and fibre type differences in subcellular lipid droplet content and distribution in elite skiers before and after exhaustive exercise

June 2017

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385 Reads

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31 Citations

Key points: Although lipid droplets in skeletal muscle are an important energy source during endurance exercise, our understanding of lipid metabolism in this context remains incomplete. Using transmission electron microscopy, two distinct subcellular pools of lipid droplets can be observed in skeletal muscle - one beneath the sarcolemma and the other between myofibrils. At rest, well-trained leg muscles of cross-country skiers contain 4- to 6-fold more lipid droplets than equally well-trained arm muscles, with a 3-fold higher content in type 1 than in type 2 fibres. During exhaustive exercise, lipid droplets between the myofibrils but not those beneath the sarcolemma are utilised by both type 1 and 2 fibres. These findings provide insight into compartmentalisation of lipid metabolism within skeletal muscle fibres. Abstract: Although the intramyocellular lipid pool is an important energy store during prolonged exercise, our knowledge concerning its metabolism is still incomplete. Here, quantitative electron microscopy was used to examine subcellular distribution of lipid droplets in type 1 and 2 fibres of the arm and leg muscles before and after 1 h of exhaustive exercise. Intermyofibrillar lipid droplets accounted for 85-97% of the total volume fraction, while the subsarcolemmal pool made up 3-15%. Before exercise, the volume fractions of intermyofibrillar and subsarcolemmal lipid droplets were 4- to 6-fold higher in leg than in arm muscles (P < 0.001). Furthermore, the volume fraction of intermyofibrillar lipid droplets was 3-fold higher in type 1 than in type 2 fibres (P < 0.001), with no fibre type difference in the subsarcolemmal pool. Following exercise, intermyofibrillar lipid droplet volume fraction was 53% lower (P = 0.0082) in both fibre types in arm, but not leg muscles. This reduction was positively associated with the corresponding volume fraction prior to exercise (R2 = 0.84, P < 0.0001). No exercise-induced change in the subsarcolemmal pool could be detected. These findings indicate clear differences in the subcellular distribution of lipid droplets in the type 1 and 2 fibres of well-trained arm and leg muscles, as well as preferential utilisation of the intermyofibrillar pool during prolonged exhaustive exercise. Apparently, the metabolism of lipid droplets within a muscle fibre is compartmentalised.


Resting blood flow and the effect of nitric oxide synthase inhibition alone (L-NMMA) or in combination with inhibition of cyclooxygenase (L-NMMA + INDO) on different muscle parts of m. quadriceps femoris at rest. VI m. vastus intermedius, RF m. rectus femoris, VM m. vastus medialis, and VL m. vastus lateralis. #p < 0.05 as compared to VL and RF, ***p < 0.001 drug effect compared to control
Exercise blood flow and the effect of nitric oxide synthase inhibition alone (L-NMMA) or in combination with inhibition of cyclooxygenase (L-NMMA + INDO) on different muscle parts of m. quadriceps femoris during exercise. VI m. vastus intermedius, RF m. rectus femoris, VM m. vastus medialis, and VL m. vastus lateralis. #p < 0.05 compared to all other muscle parts, ***p < 0.001 drug effect compared to control
The effect of nitric oxide synthase inhibition with and without inhibition of prostaglandins on blood flow in different human skeletal muscles

June 2017

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56 Reads

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12 Citations

European Journal of Applied Physiology

Purpose: Animal studies suggest that the inhibition of nitric oxide synthase (NOS) affects blood flow differently in different skeletal muscles according to their muscle fibre type composition (oxidative vs glycolytic). Quadriceps femoris (QF) muscle consists of four different muscle parts: vastus intermedius (VI), rectus femoris (RF), vastus medialis (VM), and vastus lateralis (VL) of which VI is located deep within the muscle group and is generally regarded to consist mostly of oxidative muscle fibres. Methods: We studied the effect of NOS inhibition on blood flow in these four different muscles by positron emission tomography in eight young healthy men at rest and during one-leg dynamic exercise, with and without combined blockade with prostaglandins. Results: At rest blood flow in the VI (2.6 ± 1.1 ml/100 g/min) was significantly higher than in VL (1.9 ± 0.6 ml/100 g/min, p = 0.015) and RF (1.7 ± 0.6 ml/100 g/min, p = 0.0015), but comparable to VM (2.4 ± 1.1 ml/100 g/min). NOS inhibition alone or with prostaglandins reduced blood flow by almost 50% (p < 0.001), but decrements were similar in all four muscles (drug × muscle interaction, p = 0.43). During exercise blood flow was also the highest in VI (45.4 ± 5.5 ml/100 g/min) and higher compared to VL (35.0 ± 5.5 ml/100 g/min), RF (38.4 ± 7.4 ml/100 g/min), and VM (36.2 ± 6.8 ml/100 g/min). NOS inhibition alone did not reduce exercise hyperemia (p = 0.51), but combined NOS and prostaglandin inhibition reduced blood flow during exercise (p = 0.002), similarly in all muscles (drug × muscle interaction, p = 0.99). Conclusion: NOS inhibition, with or without prostaglandins inhibition, affects blood flow similarly in different human QF muscles both at rest and during low-to-moderate intensity exercise.


Oxidative capacity and glycogen content increase more in arm than leg muscle in sedentary women after intense training

May 2015

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255 Reads

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41 Citations

Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology

The hypothesis that the adaptive capacity is higher in human upper- than lower-body skeletal muscle was tested. Furthermore, the hypothesis that more pronounced adaptations in upper-body musculature can be achieved by 'low-volume high-intensity' as compared to 'high-volume low-intensity' exercise training was evaluated. A group of sedentary premenopausal women aged 45±6 years (±SD) with expected high adaptive potential in both upper- and lower-extremity muscle groups participated. After random allocation to high-intensity swimming (HIS, n=21), moderate-intensity swimming (MOS, n=21), soccer (SOC, n=21) or a non-training control group (CON, n=20), the training groups completed three workouts per week for 15 weeks. Resting muscle biopsies were obtained from m. vastus lateralis and m. deltoideus before and after the intervention. After the training intervention, a larger (P<0.05) increase existed in m. deltoideus of the HIS group compared to m. vastus lateralis of the SOC group for citrate synthase maximal activity (95±89 vs. 27±34%), citrate synthase protein expression (100±29 vs. 31±44%), 3-hydroxyacyl-CoA dehydrogenase maximal activity (35±43 vs. 3±25%), muscle glycogen content (63±76 vs. 20±51%) and expression of mitochondrial complex II, III and IV. Additionally, HIS caused higher (P<0.05) increases than MOS in m. deltoideus citrate synthase maximal activity, citrate synthase protein expression, and muscle glycogen content. In conclusion, m. deltoideus has a higher adaptive potential than m. vastus lateralis in sedentary women, and 'high-intensity low-volume' training is a more efficient regime than 'low-intensity high-volume' training for increasing the aerobic capacity of m. deltoideus. Copyright © 2015, Journal of Applied Physiology.



Algogenic substances and metabolic status in work-related Trapezius Myalgia: a multivariate explorative study

October 2014

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307 Reads

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18 Citations

This study compares the levels of algesic substances between subjects with trapezius myalgia (TM) and healthy controls (CON) and explores the multivariate correlation pattern between these substances, pain, and metabolic status together with relative blood flow changes reported in our previous paper (Eur J Appl Physiol 108:657–669, 2010). 43 female workers with (TM) and 19 females without (CON) trapezius myalgia were – using microdialysis - compared for differences in interstitial concentrations of interleukin-6 (IL-6), bradykinin (BKN), serotonin (5-HT), lactate dehydrogenas (LDH), substance P, and N-terminal propeptide of procollagen type I (PINP) in the trapezius muscle at rest and during repetitive/stressful work. These data were also used in multivariate analyses together with previously presented data (Eur J Appl Physiol 108:657–669, 2010): trapezius muscle blood flow, metabolite accumulation, oxygenation, and pain development and sensitivity. Substance P was significantly elevated in TM (p=0.0068). No significant differences were found in the classical algesic substances (p: 0.432-0.926). The multivariate analysis showed that blood flow related variables, interstitial concentrations of metabolic (pyruvate), and algesic (BKN and K+) substances were important for the discrimination of the subjects to one of the two groups (R2: 0.19-0.31, p<0.05). Pain intensity was positively associated with levels of 5-HT and K+ and negatively associated with oxygenation indicators and IL-6 in TM (R2: 0.24, p<0.05). A negative correlation existed in TM between mechanical pain sensitivity of trapezius and BKN and IL-6 (R2: 0.26-0.39, p<0.05). The present study increased understanding alterations in the myalgic muscle. When considering the system-wide aspects, increased concentrations of lactate, pyruvate and K+ and decreased oxygenation characterized TM compared to CON. There are three major possible explanations for this finding: the workers with pain had relatively low severity of myalgia, metabolic alterations preceded detectable alterations in levels of algesics, or peripheral sensitization and other muscle alterations existed in TM. Only SP of the investigated algesic substances was elevated in TM. Several of the algesics were of importance for the levels of pain intensity and mechanical pain sensitivity in TM. These results indicate peripheral contribution to maintenance of central nociceptive and pain mechanisms and may be important to consider when designing treatments.


Regulation of the skeletal muscle blood flow in humans

September 2014

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1,353 Reads

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101 Citations

New Findings What is the topic of this review? This review highlights recent advances in our knowledge about the control of skeletal muscle blood flow during exercise in humans. What advances does it highlight? In recent years, it has become evident that the control of skeletal muscle blood flow is an interaction between various vasodilator agents, including nitric oxide, prostaglandins and adenosine. Adenosine triphosphate could play multiple roles by inducing local vasodilatation, overriding local sympathetic vasoconstriction and stimulating the exercise pressor reflex. In humans, skeletal muscle blood flow is regulated by an interaction between several locally formed vasodilators, including NO and prostaglandins. In plasma, ATP is a potent vasodilator that stimulates the formation of NO and prostaglandins and, very importantly, can offset local sympathetic vasoconstriction. Adenosine triphosphate is released into plasma from erythrocytes and endothelial cells, and the plasma concentration increases in both the feed artery and the vein draining the contracting skeletal muscle. Adenosine also stimulates the formation of NO and prostaglandins, but the plasma adenosine concentration does not increase during exercise. In the skeletal muscle interstitium, there is a marked increase in the concentration of ATP and adenosine, and this increase is tightly coupled to the increase in blood flow. The sources of interstitial ATP and adenosine are thought to be skeletal muscle cells and endothelial cells. In the interstitium, both ATP and adenosine stimulate the formation of NO and prostaglandins, but ATP has also been suggested to induce vasoconstriction and stimulate afferent nerves that signal to increase sympathetic nerve activity. Adenosine has been shown to contribute to exercise hyperaemia, whereas the role of ATP remains uncertain due to lack of specific purinergic receptor blockers for human use. The purpose of this review is to address the interaction between vasodilator systems and to discuss the multiple proposed roles of ATP in human skeletal muscle blood flow regulation.


Chronic hypoxia increases arterial blood pressure and reduces adenosine and ATP induced vasodilatation in skeletal muscle in healthy humans

June 2014

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127 Reads

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21 Citations

Acta Physiologica

Aims: To determine the role played by adenosine, ATP and chemoreflex activation on the regulation of vascular conductance in chronic hypoxia. Methods: The vascular conductance response to low and high doses of adenosine and ATP was assessed in ten healthy men. Vasodilators were infused into the femoral artery at sea level and then after 8-12 days of residence at 4559 m above sea level. At sea level, the infusions were carried out while the subjects breathed room air, acute hypoxia (FI O2 = 0.11) and hyperoxia (FI O2 = 1); and at altitude (FI O2 = 0.21 and 1). Skeletal muscle P2Y2 receptor protein expression was determined in muscle biopsies after 4 weeks at 3454 m by Western blot. Results: At altitude, mean arterial blood pressure was 13% higher (91 ± 2 vs. 102 ± 3 mmHg, P < 0.05) than at sea level and was unaltered by hyperoxic breathing. Baseline leg vascular conductance was 25% lower at altitude than at sea level (P < 0.05). At altitude, the high doses of adenosine and ATP reduced mean arterial blood pressure by 9-12%, independently of FI O2 . The change in vascular conductance in response to ATP was lower at altitude than at sea level by 24 and 38%, during the low and high ATP doses respectively (P < 0.05), and by 22% during the infusion with high adenosine doses. Hyperoxic breathing did not modify the response to vasodilators at sea level or at altitude. P2Y2 receptor expression remained unchanged with altitude residence. Conclusions: Short-term residence at altitude increases arterial blood pressure and reduces the vasodilatory responses to adenosine and ATP.


Exercise performance and cardiovascular health variables in 70-year-old male soccer players compared to endurance-trained, strength-trained and untrained age-matched men

May 2014

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208 Reads

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15 Citations

Abstract The aim was to investigate performance variables and indicators of cardiovascular health profile in elderly soccer players (SP, n = 11) compared to endurance-trained (ET, n = 8), strength-trained (ST, n = 7) and untrained (UT, n = 7) age-matched men. The 33 men aged 65-85 years underwent a testing protocol including measurements of cycle performance, maximal oxygen uptake (VO2max) and body composition, and muscle fibre types and capillarisation were determined from m. vastus lateralis biopsy. In SP, time to exhaustion was longer (16.3 ± 2.0 min; P < 0.01) than in UT (+48%) and ST (+41%), but similar to ET (+1%). Fat percentage was lower (P < 0.05) in SP (-6.5% points) than UT but not ET and ST. Heart rate reserve was higher (P < 0.05) in SP (104 ± 16 bpm) than UT (+21 bpm) and ST (+24 bpm), but similar to ET (+2 bpm), whereas VO2max was not significantly different in SP (30.2 ± 4.9 ml O2 · min(-1) · kg(-1)) compared to UT (+14%) and ST (+9%), but lower (P < 0.05) than ET (-22%). The number of capillaries per fibre was higher (P < 0.05) in SP than UT (53%) and ST (42%) but similar to ET. SP had less type IIx fibres than UT (-12% points). In conclusion, the exercise performance and cardiovascular health profile are markedly better for lifelong trained SP than for age-matched UT controls. Incremental exercise capacity and muscle aerobic capacity of SP are also superior to lifelong ST athletes and comparable to endurance athletes.



Citations (80)


... However, since glycogen within upper extremity muscles are utilized among several events, it is necessary to investigate the changes in muscle glycogen content in upper extremities. To the best of our knowledge, only a few previous studies have evaluated exercise-induced changes in muscle glycogen content in upper extremity muscles (Gejl et al. 2017;Krssak et al. 2000;Ørtenblad et al. 2018;Panduro et al. 2022;Zinner et al. 2016). For instance, Gejl et al. (2017) observed the glycogen in the muscles utilization in the brachial muscle during a simulated cross-country skiing sprint race (Gejl et al. 2017), while Krssak et al. (2000) determined the temporal changes in the glycogen levels in the arm, thigh, and calf after treadmill running and during the recovery period (Krssak et al. 2000). ...

Reference:

Dynamics of muscle glycogen increase in brachial and thigh muscles with carbohydrate loading
The Muscle Fiber Profiles, Mitochondrial Content, and Enzyme Activities of the Exceptionally Well-Trained Arm and Leg Muscles of Elite Cross-Country Skiers

... ATHL showed more lipidmitochondrial contact sites than OVWE, as reported for myocytes of active and athletic populations (55), along with greater fatty acidoxidative capacity. Higher exercise-induced utilization of intramyocellular lipids may therefore protect against DAG-induced insulin resistance in physically active individuals (42,56,57). Both longitudinal training studies (58) as well as cross-sectional studies (59) also indicate a shift toward type I fibers or a more oxidative phenotype after endurance training. ...

Pronounced limb and fibre type differences in subcellular lipid droplet content and distribution in elite skiers before and after exhaustive exercise

... The nNOS plays a crucial role in modulating synaptic plasticity, regulating blood pressure, controlling smooth muscle tone through NO production at nitrergic nerve endings, and managing blood supply to skeletal muscle fibers [75][76][77][78][79]. Alterations in urothelial receptor function, neurotransmitter release, and the sensitivity and coupling of suburothelial interstitial cells can contribute to increased involuntary bladder contractions [80]. ...

The effect of nitric oxide synthase inhibition with and without inhibition of prostaglandins on blood flow in different human skeletal muscles

European Journal of Applied Physiology

... However, no significant relationships in the changes between the two muscles were observed, suggesting that the changes were not always consistent between the muscles within each participant. Some studies have reported metabolic and mechanical differences between upper and lower extremity muscles (Huang et al. 2019;Nielsen et al. 2011;Nordsborg et al. 2015;Panduro et al. 2022), affecting muscle fiber composition (Kiilerich et al. 2008), glucose transporter 4 (GLUT-4) density (Goodyear et al. 1991), and glucose clearance (Olsen et al. 2005). Actually et al. (2011) demonstrated that there were different muscle fiber compositions between triceps brachii and vastus lateralis muscles (Saltin and Gollnick 2011). ...

Oxidative capacity and glycogen content increase more in arm than leg muscle in sedentary women after intense training

Journal of Applied Physiology: Respiratory, Environmental and Exercise Physiology

... The primary limitation of the current investigation is the absence of both an exercise intervention and central hemodynamic parameters alongside each cuff condition. Moreover, although AOP determination and blood flow parameters are most easily, accurately, and reliably measured in a resting supine position, our ability to extrapolate these data to an exercising model is limited [37,48]. We can nevertheless likely infer that the hemodynamic factors including arterial blood flow would become augmented due to enhancements in sympathetic outflow along with concomitant mean arterial pressure and CO elevations [7,49]. ...

Measurement of the exercising blood flow during rhythmical muscle contractions assessed by Doppler ultrasound: Methodological considerations

Journal of Biomedical Science and Engineering

... These results indicate that NOS inhibition attenuates increases in glucose transport into the muscle cell during contraction rather than affecting glucose delivery to the muscle (which is determined largely by blood flow) (64). However, some studies from other laboratories have yielded conflicting results (14,20,23,26). It is possible that one reason for the difference in results between groups could be in relation to the timing of the glucose uptake measurements compared with when the contraction was undertaken. ...

The Effect Of Nitric Oxide Synthase Inhibition On Exchange Of Glucose And Free Fatty Acids In Human Skeletal Muscle
  • Citing Article
  • May 2011

Medicine and Science in Sports and Exercise

... Finally, the anterior thigh muscles are large enough for physiological alterations to occur throughout the body, such as increases in oxygen consumption and blood lactate concentrations, further increasing the possibilities for investigating the physiology of exercise. [1][2][3]6,13,14 . Thus, future research centers can use the present study to build a DKE ergometer and investigate motor behavior or physiological aspects related to exercise. ...

Assessment of voluntary rhythmic muscle contraction-induced exercising blood flow variability measured by Doppler ultrasound

Open Journal of Molecular and Integrative Physiology

... Вследствие стимуляции окончаний периферических нервов накопленными метаболитами формируется дисфункция чувствительных нервов, активируется механизм отраженной боли, развиваются гипералгезия и аллодиния. Раздражение симпатической нервной системы вызывает сужение сосудов, ухудшение кровотока, образуя тем самым порочный круг [23][24][25]. Помимо этого существует теория энергетического кризиса мышечных волокон. Она заключается в том, что перегрузка мышечных волокон может возникать вследствие регулярной однотипной или излишне длительной деятельности, вызывая гипоксию и ишемию. ...

Algogenic substances and metabolic status in work-related Trapezius Myalgia: a multivariate explorative study

... Impaired delivery of oxygen and nutrients, and improper removal of waste products can contribute to the loss of muscle mass (Prior et al. 2016). Nitric oxide (NO) is a potent regulator of vasodilation and blood flow, and plays important roles within muscle at rest and during exercise (Mortensen and Saltin 2014). Importantly, when NO levels deviate above or below physiologically homeostatic levels, it can also behave as a reactive nitrogen species (Di Meo et al. 2016). ...

Regulation of the skeletal muscle blood flow in humans

... Kidney damage caused by hypertension involves a variety of complex molecular mechanisms, including the reninangiotensin-aldosterone system, oxidative stress, endothelial dysfunction, and genetic and epigenetic factors [22], while clinically it is mainly manifested as persistent proteinuria [23], which also indicates that patients may face some adverse prognosis [24]. Cardiovascular adaptation in high-altitude environments is mainly related to factors such as sympathetic nervous system activation, myocardial suppression effect, hypocapnia, reduced blood volume, increased blood viscosity, and pulmonary hypertension [25]. HARS patients have elevated blood pressure, but this is mainly due to hypoxia at high altitudes. ...

Chronic hypoxia increases arterial blood pressure and reduces adenosine and ATP induced vasodilatation in skeletal muscle in healthy humans
  • Citing Article
  • June 2014

Acta Physiologica