Early Time Course of Akt Phosphorylation after Endurance and Resistance Exercise

2010 ◽  
Vol 42 (10) ◽  
pp. 1843-1852 ◽  
Author(s):  
DONNY M. CAMERA ◽  
JOHANN EDGE ◽  
MICHAEL J. SHORT ◽  
JOHN A. HAWLEY ◽  
VERNON G. COFFEY
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.


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.).


2021 ◽  
Author(s):  
Alfonso Gonzalo De la Rubia ◽  
María Luz Centeno ◽  
Victor Moreno-González ◽  
María De Castro ◽  
Penélope García-Angulo

Common bean (Phaseolus vulgaris L.) is attacked by several pathogens such as the biotrophic gamma-proteobacterium Pseudomonas syringae pv. phaseolicola (Pph). In order to study the Pph-bean interaction during the first stages of infection, leaf disks of a susceptible bean variety named Riñón were infected with a pathogenic Pph. Using this experimental system, six new putative Wall-Associated Kinase (WAKs) receptors, previously identified in silico, were tested. These six bean WAKs (PvWAKs) showed high protein sequence homology to the well-described Arabidopsis WAK1 (AtWAK1) receptor and, by phylogenetic analysis, clustered together with AtWAKs. The expression of PvWAK1 increased at very early stages after the Pph infection. Time course experiments were performed to evaluate the accumulation of apoplastic H2O2, Ca2+ influx, total H2O2, antioxidant enzymatic activities, lipid peroxidation, and the concentrations of abscisic acid (ABA) and salicylic acid (SA), as well as the expression of six defense-related genes – MEKK-1, MAPKK, WRKY33, RIN4, PR1 and NPR1. The results showed that overexpression of PR1 occurred 2 h after Pph infection without a concomitant increase in SA levels. Although apoplastic H2O2 increased after infection, the oxidative burst was neither intense nor rapid and an efficient antioxidant response did not occur, suggesting that the observed cellular damage was due to the initial increase in total H2O2 at early time points after infection. In conclusion, the Riñón variety can perceive the presence of Pph, but this recognition only results in a modest and slow activation of host defenses, leading to high susceptibility to Pph.


2005 ◽  
Vol 99 (4) ◽  
pp. 1576-1581 ◽  
Author(s):  
Carlos L. del Rio ◽  
Patrick I. McConnell ◽  
Bradley D. Clymer ◽  
Roger Dzwonczyk ◽  
Robert E. Michler ◽  
...  

Changes in myocardial electrical impedance (MEI) and physiological end points have been correlated during acute ischemia. However, the importance of MEI's early time course is not clear. This study evaluates such significance, by comparing the temporal behavior of MEI during acute total occlusion of the left anterior descending coronary artery in anesthetized humans, dogs, and pigs. Here, interspecies differences in three MEI parameters (baseline, time to plateau onset, and plateau value normalized by baseline) were evaluated using Kruskal-Wallis ANOVA and post hoc tests ( P < 0.05). Noteworthy differences in the MEI time to plateau onset were observed: In dogs, MEI ischemic plateau was reached after 46.3 min (SD 12.9) min of occlusion, a significantly longer period compared with that of pigs and humans [4.7 (SD 1.2) and 4.1 min (SD 1.9), respectively]. However, no differences could be observed between both animal species regarding the normalized MEI ischemic plateau value (15.3% (SD 4.7) in pigs, vs. 19.6% (SD 2.6) in dogs). For all studied MEI parameters, only swine values resembled those of humans. The severity of myocardial supply ischemia, resulting from coronary artery occlusion, is known to be dependent on collateral flow. Thus, because dogs possess a well-developed collateral system (unlike humans or pigs), they have shown superior resistance to occlusion of a coronary artery. Here, the early MEI time course after left anterior descending coronary artery occlusion, represented by the time required to reach ischemic plateau, was proven to reflect such interspecies differences.


Endocrine ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 396-403 ◽  
Author(s):  
Mahdieh Molanouri Shamsi ◽  
Zuhair Mohammad Hassan ◽  
LeBris S. Quinn ◽  
Reza Gharakhanlou ◽  
Leila Baghersad ◽  
...  

2002 ◽  
Vol 115 (7) ◽  
pp. 1373-1382 ◽  
Author(s):  
Kari L. Weber ◽  
William M. Bement

The microtubule, F-actin, and intermediate filament systems are often studied as isolated systems, yet the three display mutual interdependence in living cells. To overcome limitations inherent in analysis of polymer-polymer interactions in intact cells, associations between these systems were assessed in Xenopus egg extracts. In both fixed and unfixed extract preparations, cytokeratin associated with F-actin cables that spontaneously assembled in the extracts. Time-course experiments revealed that at early time points cytokeratin cables were invariably associated with F-actin cables,while at later time points they could be found without associated F-actin. In extract samples where F-actin assembly was prevented, cytokeratin formed unorganized aggregates rather than cables. Dynamic imaging revealed transport of cytokeratin by moving F-actin as well as examples of cytokeratin release from F-actin. Experimental alteration of F-actin network organization by addition of α-actinin resulted in a corresponding change in the organization of the cytokeratin network. Finally, pharmacological disruption of the F-actin network in intact, activated eggs disrupted the normal pattern of cytokeratin assembly. These results provide direct evidence for an association between F-actin and cytokeratin in vitro and in vivo, and indicate that this interaction is necessary for proper cytokeratin assembly after transition into the first mitotic interphase of Xenopus.


1995 ◽  
Vol 269 (2) ◽  
pp. R432-R436 ◽  
Author(s):  
D. Greenberg ◽  
R. A. Kava ◽  
D. R. Lewis ◽  
M. R. Greenwood ◽  
G. P. Smith

The early time course of the absorption of duodenally infused 14C-labeled Intralipid into either the hepatic portal circulation or systemic circulation was measured. Plasma radioactivity did not increase significantly at either site until 30 min after the intestinal infusion began and was maximal between 60 and 120 min. In studies on the effects of intestinal lipid infusions on sham feeding in rats we find significant suppressions of sham feeding after only 10 min. Thus the time course for lipid absorption is different from that of the satiating effects of duodenally infused fats. These results are consistent with the hypothesis that the satiating effect of fats infused into the small intestine occurs before entry of absorbed fats into the blood and is not dependent on recently absorbed circulating fat.


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