scholarly journals Hepatic LC3 II/I ratio is not modulated in exercised mice

2020 ◽  
pp. 1103-1111
Author(s):  
B.B. Marafon ◽  
A.P. Pinto ◽  
A.L. Da Rocha ◽  
R.L. Rovina ◽  
J.R. Pauli ◽  
...  

Autophagy plays an essential role in body homeostasis achievement. One of the main proteins involved in this process is the LC3I, which, after lipidation, leads to the formation of LC3II that participates in the formation and maturation of autophagosome. This descriptive study verified the responses of LC3II to LC3I proteins, as well as the time-course of this ratio in mice livers after different types of acute physical exercise protocols. Eight-week-old male C57BL/6 mice were maintained three per cage with controlled temperature (22±2 °C) on a 12:12-h light-dark normal cycle with food (Purina chow) and water ad libitum. Mice were randomly divided into four groups: control (CT, sedentary mice), resistance (RE, submitted to a single bout of resistance exercise), endurance (EE, submitted to a single bout of endurance exercise), and concurrent (CE, submitted to a single bout of endurance combined with resistance exercise). The mice livers were extracted and used for the immunoblotting technique. The hepatic LC3B II/I ratio for the RE and EE groups were not altered during the different time-points. For the CE group, there was a decrease in this ratio 12h after exercise compared to time 0 and 18h. Also, the hepatic LC3B II/I ratios were not different among the acute physical exercise protocols along the time-course. The hepatic LC3B II/I ratio was not influenced by the endurance and resistance protocols but decreased in response to the concurrent protocol at 12h after the stimulus.

2002 ◽  
Vol 93 (1) ◽  
pp. 394-403 ◽  
Author(s):  
Fadia Haddad ◽  
Gregory R. Adams

Training protocols apply sequential bouts of resistance exercise (RE) to induce the cellular and molecular responses necessary to produce compensatory hypertrophy. This study was designed to 1) define the time course of selected cellular and molecular responses to a single bout of RE and 2) examine the effects of interbout rest intervals on the summation of these responses. Rat muscles were exposed to RE via stimulation of the sciatic nerve in vivo. Stimulated and control muscles were obtained at various time points post-RE and analyzed via Western blot and RT-PCR. A single bout of RE increased intracellular signaling (i.e., phosphorylations) and expression of mRNAs for insulin-like growth factor-I system components and myogenic markers (e.g., cyclin D1, myogenin). A rest interval of 48 h between RE bouts resulted in much greater summation of myogenic responses than 24- or 8-h rest intervals. This experimental approach should be useful for studying the regulatory mechanisms that control the hypertrophy response. These methods could also be used to compare and contrast different exercise parameters (e.g., concentric vs. eccentric, etc.).


Author(s):  
Alexander Schenk ◽  
Niklas Joisten ◽  
David Walzik ◽  
Christina Koliamitra ◽  
Daria Schoser ◽  
...  

Abstract Purpose The programmed cell death protein 1 (PD-1) has become a promising target in cancer immunotherapy. PD-1 expression of CD8+ T-cells may be increased via the exploitation of aryl hydrocarbon receptor (AhR) signaling with kynurenine (KYN) as a ligand. Since exercise affects KYN metabolism, we exploratory investigated the influence of acute exercise bouts on AhR and PD-1 levels of CD8+ T-cells. Method In this study, 24 healthy males (age: 24.6 ± 3.9 years; weight 83.9 ± 10.5 kg; height: 182.4 ± 6.2 cm) completed a single bout of endurance (EE) and resistance exercise (RE) in a randomly assigned order on separate days. Blood samples were drawn before (t0), after (t1), and 1 h after (t2) both conditions. T-cell populations, the level of cytoplasmic AhR, and surface PD-1 were assessed by flow cytometry. Results T-cell populations changed over time, indicated by an increase in the absolute numbers of CD3+ lymphocytes after EE (p < .001) and RE (p = .036) and in PD-1+ CD8+ T-cells after EE (p = .021). Proportions of T-cell populations changed only after EE (t0–t2: p = .029; t1-t2: p = .006). The level of cytoplasmic AhR decreased immediately after exercise in both exercise conditions (EE: p = .009; RE: p = .036). The level of surface PD-1 decreased 1 h after EE (p = .005). Conclusion We analyzed the level of surface PD-1 and cytoplasmic AhR following acute physical exercise for the first time. Especially EE was observed to impact both AhR and PD-1 levels, undermining its role as the AhR-PD-1 axis modulator. These results provide new insights into the impact of exercise on AhR-signaling, which could potentially be relevant for various chronic diseases.


2020 ◽  
Vol 17 (5) ◽  
pp. 575-584
Author(s):  
Diego de Alcantara Borba ◽  
Eduardo da Silva Alves ◽  
João Paulo Pereira Rosa ◽  
Lucas Alves Facundo ◽  
Carlos Magno Amaral Costa ◽  
...  

Background: Physical exercise plays an important role in metabolic health, especially in the insulin-like growth factor-1 (IGF-1) system. The objective of this study was to perform a systematic review and meta-analysis to evaluate the effects of a single endurance and resistance exercise session on IGF-1 serum. Methods: The systematic review was performed in SPORTDiscus, MEDLINE, PubMed, and Google Scholar databases. All analyses are based on random-effect models. The study identified 249 records of which 21 were included. Results: There was an effect of endurance exercise on total IGF-1 (P = .01), but not for free IGF-1 (P = .36). Resistance exercise similarly only affected total IGF-1 (P = .003) and not free IGF-1 (P = .37). The effect size indicated that total IGF-1 is more affected (ES = 0.81) by endurance than by resistance exercise (ES = 0.46). The present study showed that IGF-1 serum concentrations are altered by exercise type, but in conditions which are not well-defined. Conclusions: The systematic review and meta-analysis suggest that there is no determinant in serum IGF-1 changes for the exercise load characteristic. Therefore, physical exercise may be an alternative treatment to control changes in IGF-1 metabolism and blood concentration.


1998 ◽  
Vol 3 (4) ◽  
pp. 271-280 ◽  
Author(s):  
Hannah Steinberg ◽  
Briony R. Nicholls ◽  
Elizabeth A. Sykes ◽  
N. LeBoutillier ◽  
Nerina Ramlakhan ◽  
...  

Mood improvement immediately after a single bout of exercise is well documented, but less is known about successive and longer term effects. In a “real-life” field investigation, four kinds of exercise class (Beginners, Advanced, Body Funk and Callanetics) met once a week for up to 7 weeks. Before and after each class the members assessed how they felt by completing a questionnaire listing equal numbers of “positive” and “negative” mood words. Subjects who had attended at least five times were included in the analysis, which led to groups consisting of 18, 20, 16, and 16 subjects, respectively. All four kinds of exercise significantly increased positive and decreased negative feelings, and this result was surprisingly consistent in successive weeks. However, exercise seemed to have a much greater effect on positive than on negative moods. The favorable moods induced by each class seemed to have worn off by the following week, to be reinstated by the class itself. In the Callanetics class, positive mood also improved significantly over time. The Callanetics class involved “slower,” more demanding exercises, not always done to music. The Callanetics and Advanced classes also showed significantly greater preexercise negative moods in the first three sessions. However, these differences disappeared following exercise. Possibly, these two groups had become more “tolerant” to the mood-enhancing effects of physical exercise; this may be in part have been due to “exercise addiction.”


2019 ◽  
Vol 44 (3) ◽  
pp. 309-319 ◽  
Author(s):  
Joshua S. Jackman ◽  
Phillip G. Bell ◽  
Simone Gill ◽  
Ken van Someren ◽  
Gareth W. Davison ◽  
...  

A variety of strategies exist to modulate the acute physiological responses following resistance exercise aimed at enhancing recovery and/or adaptation processes. To assess the true impact of these strategies, it is important to know the ability of different measures to detect meaningful change. We investigated the sensitivity of measures used to quantify acute physiological responses to resistance exercise and constructed a physiological profile to characterise the magnitude of change and the time course of these responses. Eight males accustomed to regular resistance exercise performed experimental sessions during a “control week”, void of an exercise stimulus. The following week, termed the “exercise week”, participants repeated this sequence of experimental sessions, and they also performed a bout of lower-limb resistance exercise following the baseline assessments. Assessments were conducted at baseline and at 2, 6, 24, 48, 72, and 96 h after the intervention. On the basis of the signal-to-noise ratio, the most sensitive measures were maximal voluntary isometric contraction, 20-m sprint, countermovement jump peak force, rate of force development (100–200 ms), muscle soreness, Daily Analysis Of Life Demands For Athletes part B, limb girth, matrix metalloproteinase-9, interleukin-6, creatine kinase, and high-sensitivity C-reactive protein with ratios >1.5. Clear changes in these measures following resistance exercise were determined via magnitude-based inferences. These findings highlight measures that can detect real changes in acute physiological responses following resistance exercise in trained individuals. Researchers investigating strategies to manipulate acute physiological responses for recovery and/or adaptation can use these measures, as well as the recommended sampling points, to be confident that their interventions are making a worthwhile impact.


2018 ◽  
Vol 9 ◽  
Author(s):  
Tamás Nagy ◽  
Emese Kátai ◽  
Viktória Fisi ◽  
Tamás Tibor Takács ◽  
Antal Stréda ◽  
...  

2014 ◽  
Vol 19 (2) ◽  
pp. 64-71 ◽  
Author(s):  
Lausanne B.C.C. Rodrigues ◽  
Cláudia L.M. Forjaz ◽  
Aluísio H.R.A. Lima ◽  
Alessandra S. Miranda ◽  
Sérgio L.C. Rodrigues ◽  
...  

2021 ◽  
pp. 111672
Author(s):  
Sandra Aires Ferreira ◽  
Angelica Miki Stein ◽  
Natã Gomes de Lima Stavinski ◽  
Denilson de Castro Teixeira ◽  
Marcos Roberto Queiroga ◽  
...  

1999 ◽  
Vol 276 (1) ◽  
pp. E118-E124 ◽  
Author(s):  
S. M. Phillips ◽  
K. D. Tipton ◽  
A. A. Ferrando ◽  
R. R. Wolfe

We examined the effect of resistance training on the response of mixed muscle protein fractional synthesis (FSR) and breakdown rates (FBR) by use of primed constant infusions of [2H5]phenylalanine and [15N]phenylalanine, respectively, to an isolated bout of pleiometric resistance exercise. Trained subjects, who were performing regular resistance exercise (trained, T; n = 6), were compared with sedentary, untrained controls (untrained, UT; n = 6). The exercise test consisted of 10 sets (8 repetitions per set) of single-leg knee flexion (i.e., pleiometric muscle contraction during lowering) at 120% of the subjects’ predetermined single-leg 1 repetition maximum. Subjects exercised one leg while their contralateral leg acted as a nonexercised (resting) control. Exercise resulted in an increase, above resting, in mixed muscle FSR in both groups (UT: rest, 0.036 ± 0.002; exercise, 0.0802 ± 0.01; T: rest, 0.045 ± 0.004; exercise, 0.067 ± 0.01; all values in %/h; P< 0.01). In addition, exercise resulted in an increase in mixed muscle FBR of 37 ± 5% (rest, 0.076 ± 0.005; exercise, 0.105 ± 0.01; all values in %/h; P < 0.01) in the UT group but did not significantly affect FBR in the T group. The resulting muscle net balance (FSR − FBR) was negative throughout the protocol ( P < 0.05) but was increased in the exercised leg in both groups ( P < 0.05). We conclude that pleiometric muscle contractions induce an increase in mixed muscle protein synthetic rate within 4 h of completion of an exercise bout but that resistance training attenuates this increase. A single bout of pleiometric muscle contractions also increased the FBR of mixed muscle protein in UT but not in T subjects.


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