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Alessandro Moura Zagatto - One of the best experts on this subject based on the ideXlab platform.
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creatine supplementation improves Phosphagen energy pathway during supramaximal effort but does not improve anaerobic capacity or performance
Frontiers in Physiology, 2019Co-Authors: Rodrigo Araujo Bonetti Poli, Romulo Bertuzzi, Elvis De Souza Malta, Luan Henrique Roncada, Guilherme Giannini Artioli, Alessandro Moura ZagattoAbstract:This study aimed to investigate the effects of short-duration creatine monohydrate supplementation on anaerobic capacity, anaerobic energy pathways, and time-to-exhaustion during high-intensity running. Fourteen healthy men underwent a graded exercise test followed by a "V" "O" _"2max" confirmation test, 5 submaximal efforts, and 4 supramaximal running bouts at 115% of "V" "O" _"2max" intensity (the first two supramaximal sessions were applied as familiarization trials) to measure the anaerobic capacity using two procedures; the maximum accumulated oxygen deficit (MAOD) and non-oxidative pathways energetics sum (AC[La-]+EPOCfast). The investigation was conducted in a single-blind and placebo-controlled manner, with participants performing the efforts first after being supplemented with a placebo (dextrose 20 g·day-1 for 5 days), and then, after a 7-day “placebo” washout period, they started the same procedure under creatine supplementation (20 g·day-1 for 5 days. This order was chosen due to the prolonged washout of creatine. MAOD was not different between placebo (3.35±0.65 L) and creatine conditions (3.39±0.79 L) (P=0.58) and presented a negligible effect [effect size (ES)=0.08], similar to, AC[La-]+EPOCfast (placebo condition=(3.66±0.79 Land under creatine ingestion =3.82 ± 0.85 L)(P=0.07) presenting a small effect (ES=0.20). The energetics from the Phosphagen pathway increased significantly after creatine supplementation (1.66 ± 0.40 L) compared to the placebo condition (1.55±0.42 L) (P=0.03). However, the glycolytic and oxidative pathways were not different between conditions. Furthermore, time to exhaustion did not differ between placebo (160.79 ± 37.76 s) and creatine conditions (163.64 ± 38.72) (P= 0.49). Therefore, we can conclude that creatine supplementation improves the Phosphagen energy contribution, but with no statistical effect on anaerobic capacity or time to exhaustion in supramaximal running.
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Creatine Supplementation Improves Phosphagen Energy Pathway During Supramaximal Effort, but Does Not Improve Anaerobic Capacity or Performance
'Frontiers Media SA', 2019Co-Authors: Romulo Bertuzzi, Elvis De Souza Malta, Luan Henrique Roncada, Guilherme Giannini Artioli, Rodrigo De Araujo Bonetti De Poli, Alessandro Moura ZagattoAbstract:This study aimed to investigate the effects of short-duration creatine monohydrate supplementation on anaerobic capacity (AC), anaerobic energy pathways, and time-to-exhaustion during high-intensity running. Fourteen healthy men underwent a graded exercise test (GXT) followed by a O2max confirmation test, 5 submaximal efforts, and 4 supramaximal running bouts at 115% of V˙O2max intensity (the first two supramaximal sessions were applied as familiarization trials) to measure the AC using two procedures; the maximum accumulated oxygen deficit (MAOD) and non-oxidative pathways energetics sum (AC[La-]+EPOCfast). The investigation was conducted in a single-blind and placebo-controlled manner, with participants performing the efforts first after being supplemented with a placebo (dextrose 20 g⋅day-1 for 5 days), and then, after a 7 day “placebo” washout period, they started the same procedure under creatine supplementation (20 g⋅day-1 for 5 days. This order was chosen due to the prolonged washout of creatine. MAOD was not different between placebo (3.35 ± 0.65 L) and creatine conditions (3.39 ± 0.79 L; P = 0.58) and presented a negligible effect [effect size (ES) = 0.08], similar to, AC[La-]+EPOCfast (placebo condition (3.66 ± 0.79 Land under creatine ingestion 3.82 ± 0.85 L; P = 0.07) presenting a small effect (ES = 0.20). The energetics from the Phosphagen pathway increased significantly after creatine supplementation (1.66 ± 0.40 L) compared to the placebo condition (1.55 ± 0.42 L; P = 0.03). However, the glycolytic and oxidative pathways were not different between conditions. Furthermore, time to exhaustion did not differ between placebo (160.79 ± 37.76 s) and creatine conditions (163.64 ± 38.72; P = 0.49). Therefore, we can conclude that creatine supplementation improves the Phosphagen energy contribution, but with no statistical effect on AC or time to exhaustion in supramaximal running
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anaerobic capacity estimated by the sum of both oxygen equivalents from the glycolytic and Phosphagen pathways is dependent on exercise mode running versus cycling
PLOS ONE, 2018Co-Authors: Paulo Eduardo Redkva, Willian Eiji Miyagi, Fabio Milioni, Alessandro Moura ZagattoAbstract:The purpose of this study was to verify whether the exercise modality (i.e., running and cycling) alters the magnitude of “anaerobic” capacity estimated by a single supramaximal effort (AC[La]+EPOCfast). Fourteen healthy men (age: 26±9 years) underwent a maximum incremental test and a supramaximal effort to exhaustion at 115% of the intensity associated with maximal oxygen uptake to determine the AC[La]+EPOCfast (i.e., the sum of both oxygen equivalents from the glycolytic and Phosphagen pathways), performed on both a treadmill and cycle ergometer. The maximal oxygen uptake during running was higher (p = 0.001; large effect size) vs. cycling (48.9±3.9mL·kg-1·min-1 vs. 44.8±5.5mL·kg-1·min-1 respectively). Contrarily, the oxygen equivalent from the glycolytic metabolism was not different between exercise modalities (p = 0.133; small effect size; running = 2.35±0.48 L and cycling = 2.18±0.58 L). Furthermore, the “anaerobic” capacity was likely meaning fully (3.65±0.70 L) and very likely meaningfully (949.1±5.7 mL·kg-1) greater in running than cycling (3.81±0.71 L and 52.0±8.1 mL·kg-1). Additionally, the contribution of the Phosphagen metabolism was higher (p = 0.001; large effect size) for running compared to cycling (1.6±0.3 L vs.1.3±0.3 L respectively). Therefore, the “anaerobic” capacity estimated by the sum of both oxygen equivalents from the glycolytic and Phosphagen pathways during a supramaximal effort is influenced by exercise modality and is able to identify the difference in Phosphagen metabolic contribution, based on the methodological conditions of this study.
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the sensitivity of the alternative maximal accumulated oxygen deficit method to discriminate training status
Journal of Sports Sciences, 2017Co-Authors: Alessandro Moura Zagatto, Willian Eiji Miyagi, Fabio Milioni, Rodrigo De Araujo Bonetti De Poli, Fabio Yuzo Nakamura, Johnny Padulo, Nicola Luigi Bragazzi, Marcelo PapotiAbstract:ABSTRACTThe purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAODALT) method to discriminate the “anaerobic” capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAODALT. MAODALT was calculated as the sum of oxygen equivalents from the Phosphagen and glycolytic metabolic pathways. MAODALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg−1) than in ET (56.8 ± 5.4 mL · kg−1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg−1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg−1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAODALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between...
Tomohiko Suzuki - One of the best experts on this subject based on the ideXlab platform.
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CHAPTER 2 EARLY EVOLUTION OF THE CREATINE KINASE GENE FAMILY AND THE CAPACITY FOR CREATINE BIOSYNTHESIS AND MEMBRANE TRANSPORT
2020Co-Authors: Ross W Ellington, Tomohiko SuzukiAbstract:Abstract: The creatine kinase (CK)/phosphocreatine (PCr) energy buffering system is widespread in animal groups. Recent genomic sequencing and experimental results support the view that the capacity for creatine biosynthesis and membrane transport may have evolved quite early, perhaps coincident with CK. Conventional wisdom would suggest that CK evolved from an ancestral protein most similar to the CK homologue, arginine kinase. This early CK gene subsequently diverged into the cytoplasmic, mitochondrial and flagellar CK gene families. It is now clear that both the mitochondrial and cytoplasmicflagellar genes were present prior to the divergence of sponges from the multi-cellular animal (metazoan) lineage, possibly as long as a billion years ago. Sponges constitute the most ancient, extant metazoan group. It is likely that the primary function of the CKPCr system in these primitive animals was to mitigate reaction-diffusion constraints in highly polarized cells such as spermatozoa and choanocytes, the water current generating cells in sponges CELLULAR REQUISITES FOR CK-BASED ATP, INORGANIC PHOSPHATE AND PROTON BUFFERING Creatine kinase (CK) is a member of a highly conserved family of phosphoryl transfer enzymes called Phosphagen (guanidino) kinases. Phosphagen kinases catalyze the reversible transfer of phosphate from a phosphorylated guanidine compound (Phosphagen) to ADP yielding ATP and the guanidino substrate. In addition to CK, a broad range of other Phosphagen kinases have been discovered and characterized including arginine, glycocyamine, hypotaurocyamine, lombricine, opheline, taurocyamine and thalassemine kinases (reviewed b
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characterization of arginine kinase from the caenogastropod semisulcospira libertina an intermediate host of paragonimus westermani
Journal of Molluscan Studies, 2014Co-Authors: Blanca R Jarilla, Luz P Acosta, Tomohiko Suzuki, Misako Urabe, Tomonori AgatsumaAbstract:Arginine kinase (AK) belongs to the Phosphagen kinase (PK) family of enzymes that have a significant role in the maintenance of energy homeostasis. In this study, cDNA of Semisulcospira libertina AK was determined, cloned and the recombinant protein was expressed as fusion protein with maltose-binding protein. The protein has a theoretical molecular mass of 39,412 Da and an estimated isoelectric point (p I) of 6.37. The recombinant enzyme showed high affinity and significant activity only for the substrate L-arginine (Km ¼ 0.53 mM; Vmax ¼ 61.30 mmol/min mg protein). Phylogenetic analyses showed that S. libertina AK clusters with gastropod and cephalopod AKs. Comparison of gene structure showed that all intron positions of S. libertina AK are shared with molluscan AKs. Certain intron positions are also shared with trematode TK and sipunculid HTK. Semisulcospira libertina AK can be utilized in the control of paragonimiasis since it is absent in mammalian hosts.
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gene structure of the two domain taurocyamine kinase from paragonimus westermani evidence for a distinct lineage of trematode Phosphagen kinases
FEBS Letters, 2013Co-Authors: Mitsuru Nagataki, Blanca R Jarilla, Shinji Tokuhiro, Luz P Acosta, Tomohiko Suzuki, Tomonori AgatsumaAbstract:Taurocyamine kinase (TK) is an enzyme that catalyzes the reversible transfer of a phosphate between ATP and taurocyamine. Annelid TKs were suggested to have evolved from a CK ancestor. However, TKs from the lung fluke Paragonimus westermani comprised another lineage. Construction of phylogenetic tree and comparison of exon/intron organization showed that P. westermani TK and other trematode TKs evolved from a molluscan arginine kinase (AK) gene. Exon shuffling probably caused the changes in amino acid sequence thereby changing the affinity from AK to TK. The present study provides new insights on the evolution of Phosphagen kinases found in trematodes.
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The role of Arg-96 in Danio rerio creatine kinase in substrate recognition and active center configuration
International journal of biological macromolecules, 2009Co-Authors: Kouji Uda, Tamotsu Matsumoto, Ai Kuwasaki, Kanami Shima, Tomohiko SuzukiAbstract:Abstract In creatine kinases (CKs), the amino acid residue-96 is a strictly conserved arginine. This residue is not directly associated with substrate binding, but it is located close to the binding site of the substrate creatine. On the other hand, the residue-96 is known to be involved in expression in the substrate specificity of various other Phosphagen (guanidino) kinases, since each enzyme has a specific residue at this position: arginine kinase (Tyr), glycocyamine kinase (Ile), taurocyamine kinase (His) and lombricine kinase (Lys). To gain a greater understanding of the role of residue-96 in CKs, we replaced this residue in zebra fish Danio rerio cytoplasmic CK with other 19 amino acids, and expressed these constructs in Escherichia coli. All the twenty recombinant enzymes, including the wild-type, were obtained as soluble form, and their activities were determined in the forward direction. Compared with the activity of wild-type, the R96K mutant showed significant activity (8.3% to the wild-type), but 10 mutants (R96Y, A, S, E, H, T, F, C, V and N) showed a weak activity (0.056–1.0%). In the remaining mutants (R96Q, G, M, P, L, W, D and I), the activity was less than 0.05%. Our mutagenesis studies indicated that Arg-96 in Danio CK can be substituted for partially by Lys, but other replacements caused remarkable loss of activity. From careful inspection of the crystal structures (transition state analog complex (TSAC) and open state) of Torpedo cytoplasmic CK, we found that the side chain of R96 forms hydrogen bonds with A339 and D340 only in the TSAC structure. Based on the assumption that CKs consist of four dynamic domains (domains 1–3, and fixed domain), the above hydrogen bonds act to link putative domains 1 and 3 in TSAC structure. We suggest that residue-96 in CK and equivalent residues in other Phosphagen kinases, which are structurally similar, have dual roles: (1) one involves in distinguishing guanidino substrates, and (2) the other plays a key role in organizing the hydrogen-bond network around residue-96 which offers an appropriate active center for the high catalytic turnover. The mode of development of the network appears to be unique each Phosphagen kinase, reflecting evolution of each enzyme.
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toxocara canis molecular cloning characterization expression and comparison of the kinetics of cdna derived arginine kinase
Experimental Parasitology, 2007Co-Authors: Susiji Wickramasinghe, Mitsuru Nagataki, Tomohiko Suzuki, Kouji Uda, Lalani Yatawara, R P V J Rajapakse, Yoshiya Watanabe, Tomonori AgatsumaAbstract:Abstract Arginine kinase (AK) is a member of a highly conserved family of Phosphagen kinases. We determined the cDNA sequence of Toxocara canis AK, cloned it in pMAL plasmid and expressed it in Escherichia coli as a fusion protein with maltose-binding protein. The protein has a theoretical molecular mass of 45,376 Da and an estimated isoelectric point (pI) of 8.38. Alignment of the cDNA-derived amino acid sequence of T. canis AK with other Phosphagen kinase sequences showed high amino acid identity with other nematode AKs, and phylogenetic analysis placed it as a distinct branch within a nematode AK cluster. Analysis of the N-terminus sequence of T. canis AK revealed the presence of a signal targeting peptide presumably targeting this protein to cytosol or endoplasmic reticulum (ER). T. canis AK showed high activity for l -arginine. The kinetic constants (Km = 0.12 mM, Kcat = 29.18, and Kd = 0.23 mM) and Vmax (43.76 μmol Pi/min/mg protein) of T. canis recombinant-AK were determined for the forward reaction. It also exhibited a synergism for substrate binding ( K d Arg / K m Arg = 1.96 ) . Comparison of K cat / K m Arg values in various arginine kinases indicates that T. canis AK has a high catalytic efficiency (248.19 s−1 mM−1). The present study contains the first description of arginine kinase in a zoonotic nematode. The determination of T. canis AK and its Phosphagen biosynthetic pathway, which is completely different from those in mammalian host tissues, suggests this enzyme as a possible novel chemotherapy target for VLM syndrome in humans.
Michael S Chapman - One of the best experts on this subject based on the ideXlab platform.
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the michaelis complex of arginine kinase samples the transition state at a frequency that matches the catalytic rate
Journal of the American Chemical Society, 2017Co-Authors: Yu Peng, Michael S Chapman, Alexandar L Hansen, Lei Bruschweilerli, Omar Davulcu, Jack J Skalicky, Rafael BruschweilerAbstract:Arginine kinase (AK), which is a member of the Phosphagen kinase family, serves as a model system for studying the structural and dynamic determinants of biomolecular enzyme catalysis of all major states involved of the enzymatic cycle. These states are the apo state (substrate free), the Michaelis complex analogue AK:Arg:Mg·AMPPNP (MCA), a product complex analogue AK:pAIE:Mg·ADP (PCA), and the transition state analogue AK:Arg:Mg·ADP:NO3– (TSA). The conformational dynamics of these states have been studied by NMR relaxation dispersion measurements of the methyl groups of the Ile, Leu, and Val residues at two static magnetic fields. Although all states undergo significant amounts of μs–ms time scale dynamics, only the MCA samples a dominant excited state that resembles the TSA, as evidenced by the strong correlation between the relaxation dispersion derived chemical shift differences Δω and the equilibrium chemical shift differences Δδ of these states. The average lifetime of the MCA is 36 ms and the free ...
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Common Hydrogen Bond Interactions in Diverse Phosphoryl Transfer Active Sites
2014Co-Authors: Jean C. Summerton, Gregory M. Martin, Jeffrey D. Evanseck, Michael S ChapmanAbstract:Phosphoryl transfer reactions figure prominently in energy metabolism, signaling, transport and motility. Prior detailed studies of selected systems have highlighted mechanistic features that distinguish different phosphoryl transfer enzymes. Here, a top-down approach is developed for comparing statistically the active site configurations between populations of diverse structures in the Protein Data Bank, and it reveals patterns of hydrogen bonding that transcend enzyme families. Through analysis of large samples of structures, insights are drawn at a level of detail exceeding the experimental precision of an individual structure. In Phosphagen kinases, for example, hydrogen bonds with the O3b of the nucleotide substrate are revealed as analogous to those in unrelated G proteins. In G proteins and other enzymes, interactions with O3b have been understood in terms of electrostatic favoring of the transition state. Ground state quantum mechanical calculations on model compounds show that the active site interactions highlighted in our database analysis can affect substrate phosphate charge and bond length, in ways that are consistent with prior experimental observations, by modulating hyperconjugative orbital interactions that weaken the scissile bond. Testing experimentally the inference about the importance of O3b interactions in Phosphagen kinases, mutation of arginine kinase Arg280 decreases kcat, as predicted, with little impact upon KM
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induced fit in guanidino kinases comparison of substrate free and transition state analog structures of arginine kinase
Protein Science, 2003Co-Authors: Mohammad S Yousef, Thayumanasamy Somasundaram, Shawn A Clark, Pamela K Pruett, Ross W Ellington, Michael S ChapmanAbstract:Arginine kinase (AK) is a member of the guanidino kinase family that plays an important role in buffering ATP concentration in cells with high and fluctuating energy demands. The AK specifically catalyzes the reversible phosphoryl transfer between ATP and arginine. We have determined the crystal structure of AK from the horseshoe crab (Limulus polyphemus) in its open (substrate-free) form. The final model has been refined at 2.35 Å with a final R of 22.3% (Rfree = 23.7%). The structure of the open form is compared to the previously determined structure of the transition state analog complex in the closed form. Classically, the protein would be considered two domain, but dynamic domain (DynDom) analysis shows that most of the differences between the two structures can be considered as the motion between four rigid groups of nonsequential residues. ATP binds near a cluster of positively charged residues of a fixed dynamic domain. The other three dynamic domains close the active site with separate hinge rotations relative to the fixed domain. Several residues of key importance for the induced motion are conserved within the Phosphagen kinase family, including creatine kinase. Substantial conformational changes are induced in different parts of the enzyme as intimate interactions are formed with both substrates. Thus, although induced fit occurs in a number of phosphoryl transfer enzymes, the conformational changes in Phosphagen kinases appear to be more complicated than in prior examples.
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Expression, purification from inclusion bodies, and crystal characterization of a transition state analog complex of arginine kinase: a model for studying Phosphagen kinases.
Protein science : a publication of the Protein Society, 1997Co-Authors: Genfa Zhou, Thayumanasamy Somasundaram, Michael S Chapman, Gopalakrishnan Parthasarathy, Andrea Ables, Lance Roy, Scott J. Strong, W. Ross EllingtonAbstract:Phosphagen kinases catalyze the reversible transfer of a phosphoryl group between guanidino phosphate compounds and ADP, thereby regenerating ATP during bursts of cellular activity. Large quantities of highly pure arginine kinase (EC 2.7.3.3), the Phosphagen kinase present in arthropods, have been isolated from E. coli, into which the cDNA for the horseshoe crab enzyme had been cloned. Purification involves size exclusion and anion exchange chromatographies applied in the denatured and refolded states. The recombinant enzyme has been crystallized as a transition state analog complex. Near complete native diffraction data have been collected to 1.86 A resolution. Substitution of a recombinant source for a natural one, improvement in the purification, and data collection at cryo temperatures have all yielded significant improvements in diffraction.
Inna M Sokolova - One of the best experts on this subject based on the ideXlab platform.
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effects of cadmium exposure on critical temperatures of aerobic metabolism in eastern oysters crassostrea virginica gmelin 1791
Aquatic Toxicology, 2015Co-Authors: Rita Bagwe, Elia Beniash, Inna M SokolovaAbstract:Cadmium (Cd) and elevated temperatures are common stressors in estuarine and coastal environments. Elevated temperature can sensitize estuarine organisms to the toxicity of metals such as Cd and vice versa, but the physiological mechanisms of temperature-Cd interactions are not well understood. We tested a hypothesis that interactive effects of elevated temperature and Cd stress involve Cd-induced reduction of the aerobic scope of an organism thereby narrowing the thermal tolerance window of oysters. We determined the effects of prolonged Cd exposure (50 μg Cd l(-1)for 30 days) on the upper critical temperature of aerobic metabolism (assessed by accumulation of anaerobic end products L-alanine, succinate and acetate), cellular energy status (assessed by the tissue levels of adenylates, Phosphagen/aPhosphagen and glycogen and lipid reserves) and oxidative damage during acute temperature rise (20-36 °C) in the eastern oysters Crassostrea virginica. The upper critical temperature (TcII) was shifted to lower values (from 28 to 24 °C) in Cd-exposed oysters in spring and was lower in both control and Cd-exposed groups in winter (24 and <20 °C, respectively). This indicates a reduction of thermal tolerance of Cd-exposed oysters associated with a decrease of the aerobic scope of the organism and early transition to partial anaerobiosis. Acute warming had no negative effects on tissue energy reserves or parameters of cellular energy status of oysters (except a decrease in adenylate content at the extreme temperature of 36 °C) but led to an increase in oxidative lesions of proteins at extreme temperatures. These data show that transition to partial anaerobiosis (indicated by the accumulation of anaerobic end products) is the most sensitive biomarker of temperature-induced transition to energetically non-sustainable state in oysters, whereas disturbances in the cellular energy status (i.e. decline in adenylate and Phosphagen levels) and oxidative stress ensue at considerably higher temperatures, nearing the lethal range. This study indicates that long-term exposure of oysters to environmentally relevant levels of Cd may increase their sensitivity to elevated temperatures during seasonal warming and/or the global climate change in polluted estuaries.
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resistance to freshwater exposure in white sea littorina spp i anaerobic metabolism and energetics
Journal of Comparative Physiology B-biochemical Systemic and Environmental Physiology, 2000Co-Authors: Inna M Sokolova, Christian Bock, Hans-otto PörtnerAbstract:Anaerobic metabolism and changes in the osmotic concentration of extravisceral fluid were studied in the White Sea periwinkles (Littorina littorea, Littorina saxatilis and Littorina obtusata) during freshwater exposure. Resistance to hypoosmotic stress increased in the order: L. obtusata < L. saxatilis < L. littorea. Our data suggest that osmotic shock is not a primary reason for mortality of the periwinkles under these conditions. During environmental anaerobiosis, considerable succinate accumulation (up to 10–19 μmol g−1 wet weight), and depletion of Phosphagen and ATP pools were found in the studied species. Other metabolic end products (alanopine, strombine, lactate, acetate or propionate) were not detected. Succinate accumulation and net ATP breakdown were the fastest in the least resistant species, L. obtusata, and slowest in the most resistant, L. littorea. Rate of ATP turnover decreased during freshwater exposure in L. littorea and L. saxatilis, but not in L. obtusata. Our data suggest that differential resistance of three studied Littorina spp. to extreme hypoosmotic stress may be related to their different abilities to reduce metabolic rate and ATP turnover during sustained anoxia. Species-specific variations in anaerobic capacity of Littorina spp. are discussed in relation to their vertical distribution, size and ecology.
Rodrigo Araujo Bonetti Poli - One of the best experts on this subject based on the ideXlab platform.
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creatine supplementation improves Phosphagen energy pathway during supramaximal effort but does not improve anaerobic capacity or performance
Frontiers in Physiology, 2019Co-Authors: Rodrigo Araujo Bonetti Poli, Romulo Bertuzzi, Elvis De Souza Malta, Luan Henrique Roncada, Guilherme Giannini Artioli, Alessandro Moura ZagattoAbstract:This study aimed to investigate the effects of short-duration creatine monohydrate supplementation on anaerobic capacity, anaerobic energy pathways, and time-to-exhaustion during high-intensity running. Fourteen healthy men underwent a graded exercise test followed by a "V" "O" _"2max" confirmation test, 5 submaximal efforts, and 4 supramaximal running bouts at 115% of "V" "O" _"2max" intensity (the first two supramaximal sessions were applied as familiarization trials) to measure the anaerobic capacity using two procedures; the maximum accumulated oxygen deficit (MAOD) and non-oxidative pathways energetics sum (AC[La-]+EPOCfast). The investigation was conducted in a single-blind and placebo-controlled manner, with participants performing the efforts first after being supplemented with a placebo (dextrose 20 g·day-1 for 5 days), and then, after a 7-day “placebo” washout period, they started the same procedure under creatine supplementation (20 g·day-1 for 5 days. This order was chosen due to the prolonged washout of creatine. MAOD was not different between placebo (3.35±0.65 L) and creatine conditions (3.39±0.79 L) (P=0.58) and presented a negligible effect [effect size (ES)=0.08], similar to, AC[La-]+EPOCfast (placebo condition=(3.66±0.79 Land under creatine ingestion =3.82 ± 0.85 L)(P=0.07) presenting a small effect (ES=0.20). The energetics from the Phosphagen pathway increased significantly after creatine supplementation (1.66 ± 0.40 L) compared to the placebo condition (1.55±0.42 L) (P=0.03). However, the glycolytic and oxidative pathways were not different between conditions. Furthermore, time to exhaustion did not differ between placebo (160.79 ± 37.76 s) and creatine conditions (163.64 ± 38.72) (P= 0.49). Therefore, we can conclude that creatine supplementation improves the Phosphagen energy contribution, but with no statistical effect on anaerobic capacity or time to exhaustion in supramaximal running.