Beta-adrenergic blockade and lipoprotein lipase activity in rat tissues after acute exercise

1991 ◽  
Vol 261 (4) ◽  
pp. R891-R897 ◽  
Author(s):  
A. Paulin ◽  
J. Lalonde ◽  
Y. Deshaies

The present experiments were aimed at evaluating the acute effects of exercise on lipoprotein lipase (LPL) activity in untrained rats. The activity of LPL was measured in postheparin plasma (PHP) before and at various times after a 1-h run on a treadmill (22 m/min, O degrees grade). LPL in PHP was 50% below pre-exercise levels immediately and 3 h after the run but was increased 65% over resting levels 24 h postexercise. To further characterize the very early fall in LPL activity in response to exercise and to assess the possible involvement therein of the beta-adrenergic pathway, LPL in heart, vastus lateralis muscle (VLM), and white (WAT) and brown (BAT) adipose tissues was determined at rest and immediately after exercise in rats that were treated or not with nadolol (25 mg.kg-1.day-1 for 30 days). Immediately after 1 h of exercise, there was a reduction in total enzyme activity in WAT (40% below resting levels), BAT (-58%), VLM (-53%), and heart (-30%). Exercise reduced serum triacylglycerol levels (-64%) and doubled those of nonesterified fatty acids. beta-Adrenergic blockade did not affect any of these variables. Both exercise and nadolol lowered serum cholesterol levels by approximately 20%, but the effects were not additive. These results show that the global intravascular pool of LPL undergoes divergent, time-dependent alterations in response to a single bout of moderate exercise. The acute downregulation of postheparin plasma LPL immediately after exercise reflected a fall in the total enzyme pool of all tissues studied.(ABSTRACT TRUNCATED AT 250 WORDS)

1992 ◽  
Vol 262 (4) ◽  
pp. E377-E382
Author(s):  
A. Paulin ◽  
Y. Deshaies

The present studies were designed to verify whether preventing the rise in serum levels of nonesterified fatty acids (NEFA) by adrenergic blockade would interfere with the decrease in tissue lipoprotein lipase (LPL) activity caused by acute exercise in rats. Ninety minutes before being killed, male rats were injected intraperitoneally with either saline, the beta-adrenergic blocker propranolol (25 mg/kg body weight), or the alpha 2-adrenergic blocker yohimbine (3 mg/kg body weight). Half of each group was killed at rest and the other half immediately after a 1-h run on a treadmill. LPL was determined in white adipose tissue (WAT), heart, and red vastus lateralis muscle (VLM). Exercise enhanced serum levels of NEFA 50% over resting values in saline-injected rats. The latter increase was totally abolished in animals having received propranolol or yohimbine. The activity of LPL in WAT, heart, and red VLM was approximately 35% lower in exercised rats than in resting animals. Serum triacylglycerols were also reduced by the run. Neither propranolol nor yohimbine interfered with any of these reductions. Exercise did not change serum glucose levels in saline-injected rats but decreased it in those injected with propranolol or yohimbine. Serum insulin was unchanged by exercise and by the antagonists. These findings suggest that the beta- and alpha 2-adrenergic pathways, as well as the exercise-induced rise in serum levels of NEFA, are not responsible for the early reducing effect of a 1-h run on tissue LPL activity in untrained rats.(ABSTRACT TRUNCATED AT 250 WORDS)


2019 ◽  
Vol 316 (4) ◽  
pp. E605-E614 ◽  
Author(s):  
Daniil V. Popov ◽  
Pavel A. Makhnovskii ◽  
Elena I. Shagimardanova ◽  
Guzel R. Gazizova ◽  
Evgeny A. Lysenko ◽  
...  

Reduction in daily activity leads to dramatic metabolic disorders, while regular aerobic exercise training is effective for preventing this problem. The purpose of this study was to identify genes that are directly related to contractile activity in human skeletal muscle, regardless of the level of fitness. Transcriptome changes after the one-legged knee extension exercise in exercised and contralateral nonexercised vastus lateralis muscle of seven men were evaluated by RNA-seq. Transcriptome change at baseline after 2 mo of aerobic training (5/wk, 1 h/day) was evaluated as well. Postexercise changes in the transcriptome of exercised muscle were associated with different factors, including circadian oscillations. To reveal transcriptome response specific for endurance-like contractile activity, differentially expressed genes between exercised and nonexercised muscle were evaluated at 1 and 4 h after the one-legged exercise. The contractile activity-specific transcriptome responses were associated only with an increase in gene expression and were regulated mainly by CREB/ATF/AP1-, MYC/MAX-, and E2F-related transcription factors. Endurance training-induced changes (an increase or decrease) in the transcriptome at baseline were more pronounced than transcriptome responses specific for acute contractile activity. Changes after training were associated with widely different biological processes than those after acute exercise and were regulated by different transcription factors (IRF- and STAT-related factors). In conclusion, adaptation to regular exercise is associated not only with a transient (over several hours) increase in expression of many contractile activity-specific genes, but also with a pronounced change (an increase or decrease) in expression of a large number of genes under baseline conditions.


2005 ◽  
Vol 289 (1) ◽  
pp. R266-R274 ◽  
Author(s):  
A. C. Petersen ◽  
K. T. Murphy ◽  
R. J. Snow ◽  
J. A. Leppik ◽  
R. J. Aughey ◽  
...  

We investigated whether depressed muscle Na+-K+-ATPase activity with exercise reflected a loss of Na+-K+-ATPase units, the time course of its recovery postexercise, and whether this depressed activity was related to increased Na+-K+-ATPase isoform gene expression. Fifteen subjects performed fatiguing, knee extensor exercise at ∼40% maximal work output per contraction. A vastus lateralis muscle biopsy was taken at rest, fatigue, 3 h, and 24 h postexercise and analyzed for maximal Na+-K+-ATPase activity via 3- O-methylfluorescein phosphatase (3- O-MFPase) activity, Na+-K+-ATPase content via [3H]ouabain binding sites, and Na+-K+-ATPase α1-, α2-, α3-, β1-, β2- and β3-isoform mRNA expression by real-time RT-PCR. Exercise [352 (SD 267) s] did not affect [3H]ouabain binding sites but decreased 3- O-MFPase activity by 10.7 (SD 8)% ( P < 0.05), which had recovered by 3 h postexercise, without further change at 24 h. Exercise elevated α1-isoform mRNA by 1.5-fold at fatigue ( P < 0.05). This increase was inversely correlated with the percent change in 3- O-MFPase activity from rest to fatigue (%Δ3- O-MFPaserest-fatigue) ( r = −0.60, P < 0.05). The average postexercise (fatigue, 3 h, 24 h) α1-isoform mRNA was increased 1.4-fold ( P < 0.05) and approached a significant inverse correlation with %Δ3- O-MFPaserest-fatigue ( r = −0.56, P = 0.08). Exercise elevated α2-isoform mRNA at fatigue 2.5-fold ( P < 0.05), which was inversely correlated with %Δ3- O-MFPaserest-fatigue ( r = −0.60, P = 0.05). The average postexercise α2-isoform mRNA was increased 2.2-fold ( P < 0.05) and was inversely correlated with the %Δ3- O-MFPaserest-fatigue ( r = −0.68, P < 0.05). Nonsignificant correlations were found between %Δ3- O-MFPaserest-fatigue and other isoforms. Thus acute exercise transiently decreased Na+-K+-ATPase activity, which was correlated with increased Na+-K+-ATPase gene expression. This suggests a possible signal-transduction role for depressed muscle Na+-K+-ATPase activity with exercise.


2016 ◽  
Vol 120 (11) ◽  
pp. 1355-1363 ◽  
Author(s):  
Sean A. Newsom ◽  
Joseph T. Brozinick ◽  
Katja Kiseljak-Vassiliades ◽  
Allison N. Strauss ◽  
Samantha D. Bacon ◽  
...  

Several recent reports indicate that the balance of skeletal muscle phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is a key determinant of muscle contractile function and metabolism. The purpose of this study was to determine relationships between skeletal muscle PC, PE and insulin sensitivity, and whether PC and PE are dynamically regulated in response to acute exercise in humans. Insulin sensitivity was measured via intravenous glucose tolerance in sedentary obese adults (OB; n = 14), individuals with type 2 diabetes (T2D; n = 15), and endurance-trained athletes (ATH; n = 15). Vastus lateralis muscle biopsies were obtained at rest, immediately after 90 min of cycle ergometry at 50% maximal oxygen consumption (V̇o2 max), and 2-h postexercise (recovery). Skeletal muscle PC and PE were measured via infusion-based mass spectrometry/mass spectrometry analysis. ATH had greater levels of muscle PC and PE compared with OB and T2D ( P < 0.05), with total PC and PE positively relating to insulin sensitivity (both P < 0.05). Skeletal muscle PC:PE ratio was elevated in T2D compared with OB and ATH ( P < 0.05), tended to be elevated in OB vs. ATH ( P = 0.07), and was inversely related to insulin sensitivity among the entire cohort ( r = −0.43, P = 0.01). Muscle PC and PE were altered by exercise, particularly after 2 h of recovery, in a highly group-specific manner. However, muscle PC:PE ratio remained unchanged in all groups. In summary, total muscle PC and PE are positively related to insulin sensitivity while PC:PE ratio is inversely related to insulin sensitivity in humans. A single session of exercise significantly alters skeletal muscle PC and PE levels, but not PC:PE ratio.


2000 ◽  
Vol 279 (2) ◽  
pp. H772-H778 ◽  
Author(s):  
R. S. Richardson ◽  
H. Wagner ◽  
S. R. D. Mudaliar ◽  
E. Saucedo ◽  
R. Henry ◽  
...  

Angiogenesis is a component of the multifactoral adaptation to exercise training, and vascular endothelial growth factor (VEGF) is involved in extracellular matrix changes and endothelial cell proliferation. However, there is limited evidence supporting the role of VEGF in the exercise training response. Thus we studied mRNA levels of VEGF, using quantitative Northern analysis, in untrained and trained human skeletal muscle at rest and after a single bout of exercise. Single leg knee-extension provided the acute exercise stimulus and the training modality. Four biopsies were collected from the vastus lateralis muscle at rest in the untrained and trained conditions before and after exercise. Training resulted in a 35% increase in muscle oxygen consumption and an 18% increase in number of capillaries per muscle fiber. At rest, VEGF/18S mRNA levels were similar before (0.38 ± 0.04) and after (1.2 ± 0.4) training. When muscle was untrained, acute exercise greatly elevated VEGF/18S mRNA levels (16.9 ± 6.7). The VEGF/18S mRNA response to acute exercise in the trained state was markedly attenuated (5.4 ± 1.3). These data support the concept that VEGF is involved in exercise-induced skeletal muscle angiogenesis and appears to be subject to a negative feedback mechanism as exercise adaptations occur.


2012 ◽  
Vol 303 (1) ◽  
pp. E82-E89 ◽  
Author(s):  
Jørgen Jensen ◽  
Puntip Tantiwong ◽  
Jorid T. Stuenæs ◽  
Marjorie Molina-Carrion ◽  
Ralph A. DeFronzo ◽  
...  

Insulin stimulates glycogen synthase (GS) through dephosphorylation of serine residues, and this effect is impaired in skeletal muscle from insulin-resistant [obese and type 2 diabetic (T2DM)] subjects. Exercise also increases GS activity, yet it is not known whether the ability of exercise to affect GS is impaired in insulin-resistant subjects. The objective of this study was to examine the effect of acute exercise on GS phosphorylation and enzyme kinetic properties in muscle from insulin-resistant individuals. Lean normal glucose-tolerant (NGT), obese NGT, and obese T2DM subjects performed 40 min of moderate-intensity cycle exercise (70% of V̇o2max). GS kinetic properties and phosphorylation were measured in vastus lateralis muscle before exercise, immediately after exercise, and 3.5 h postexercise. In lean subjects, GS fractional activity increased twofold after 40 min of exercise, and it remained elevated after the 3.5-h rest period. Importantly, exercise also decreased GS Km for UDP-glucose from ≈0.5 to ≈0.2 mM. In lean subjects, exercise caused significant dephosphorylation of GS by 50–70% (Ser641, Ser645, and Ser645,649,653,657), and phosphorylation of these sites remained decreased after 3.5 h; Ser7 phosphorylation was not regulated by exercise. In obese NGT and T2DM subjects, exercise increased GS fractional activity, decreased Km for UDP-glucose, and decreased GS phosphorylation as effectively as in lean NGT subjects. We conclude that the molecular regulatory process by which exercise promotes glycogen synthesis in muscle is preserved in insulin-resistant subjects.


2021 ◽  
Vol 22 (3) ◽  
pp. 1208
Author(s):  
Pavel A. Makhnovskii ◽  
Roman O. Bokov ◽  
Fedor A. Kolpakov ◽  
Daniil V. Popov

Inactivity is associated with the development of numerous disorders. Regular aerobic exercise is broadly used as a key intervention to prevent and treat these pathological conditions. In our meta-analysis we aimed to identify and compare (i) the transcriptomic signatures related to disuse, regular and acute aerobic exercise in human skeletal muscle and (ii) the biological effects and transcription factors associated with these transcriptomic changes. A standardized workflow with robust cut-off criteria was used to analyze 27 transcriptomic datasets for the vastus lateralis muscle of healthy humans subjected to disuse, regular and acute aerobic exercise. We evaluated the role of transcriptional regulation in the phenotypic changes described in the literature. The responses to chronic interventions (disuse and regular training) partially correspond to the phenotypic effects. Acute exercise induces changes that are mainly related to the regulation of gene expression, including a strong enrichment of several transcription factors (most of which are related to the ATF/CREB/AP-1 superfamily) and a massive increase in the expression levels of genes encoding transcription factors and co-activators. Overall, the adaptation strategies of skeletal muscle to decreased and increased levels of physical activity differ in direction and demonstrate qualitative differences that are closely associated with the activation of different sets of transcription factors.


2009 ◽  
Vol 161 (3) ◽  
pp. 427-434 ◽  
Author(s):  
Helene Rundqvist ◽  
Eric Rullman ◽  
Carl Johan Sundberg ◽  
Helene Fischer ◽  
Katarina Eisleitner ◽  
...  

Objective:Erythropoietin receptor (EPOR) expression in non-hematological tissues has been shown to be activated by locally produced and/or systemically delivered EPO. Improved oxygen homeostasis, a well-established consequence of EPOR activation, is very important for human skeletal muscle performance. In the present study we investigate whether human skeletal muscle fibers and satellite cells express EPOR and if it is activated by exercise.Design and methodsTen healthy males performed 65 min of cycle exercise. Biopsies were obtained from the vastus lateralis muscle and femoral arterio-venous differences in EPO concentrations were estimated.ResultsThe EPOR protein was localized in areas corresponding to the sarcolemma and capillaries. Laser dissection identified EPOR mRNA expression in muscle fibers. Also, EPOR mRNA and protein were both detected in human skeletal muscle satellite cells. In the initial part of the exercise bout there was a release of EPO from the exercising leg to the circulation, possibly corresponding to an increased bioavailability of EPO. After exercise, EPOR mRNA and EPOR-associated JAK2 phosphorylation were increased.ConclusionsInteraction with JAK2 is required for EPOR signaling and the increase found in phosphorylation is therefore closely linked to the activation of EPOR. The receptor activation by acute exercise suggests that signaling through EPOR is involved in exercise-induced skeletal muscle adaptation, thus extending the biological role of EPO into the skeletal muscle.


1985 ◽  
Vol 231 (1) ◽  
pp. 217-220 ◽  
Author(s):  
R A J Challis ◽  
J R S Arch ◽  
E A Newsholme

The effects of cold-exposure, the hyperthyroid state and a single exercise bout in vivo on the maximal enzyme activities of 6-phosphofructokinase and fructose-1,6-bisphosphatase in vastus lateralis muscle and the rates of fructose 6-phosphate/fructose 1,6-bisphosphate cycling measured in epitrochlearis muscle in vitro were investigated. In all cases significant changes in substrate cycling rates were observed, whether in the absence of added hormones in vitro (acute exercise), or when stimulated by insulin plus adrenaline (cold-exposure), or with respect to the catecholamine-sensitivity of the cycling rate (the hyperthyroid state).


1986 ◽  
Vol 60 (5) ◽  
pp. 1623-1627 ◽  
Author(s):  
G. J. Bagby ◽  
J. L. Johnson ◽  
B. W. Bennett ◽  
R. E. Shepherd

Voluntary exercise of rats in freely rotating work wheels has been extensively used, but muscle adaptations that result from such exercise training are poorly documented. The purpose of this study was to determine whether the exercise performed by voluntarily active rats would increase succinate dehydrogenase or lipoprotein lipase activities in the soleus muscle (SM) or the red portion of the vastus lateralis muscle (RV). In SM the activities of these two enzymes were not increased after 7 or 16 wk of voluntary exercise. Succinate dehydrogenase activity in RV was moderately increased after 7 and 16 wk of voluntary activity (P less than 0.05). Substantial increases occurred in RV lipoprotein lipase activity (P less than 0.01). The increase in RV lipoprotein lipase activity was positively related to distance run by the rats. The results indicate that only small muscle-dependent increases in mitochondrial enzymes occur in rats allowed to exercise voluntarily in rodent work wheels. Voluntary exercise training induced a selective increase in lipoprotein lipase activity in a muscle containing a high percentage of fast-twitch red fibers, a response absent in a muscle containing a predominance of slow-twitch red fibers. It is unlikely that this differential response can be explained by exercise-induced changes in plasma hormone concentrations involved in the regulation of lipoprotein lipase.


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