Avertyshev@mail.ru: /* Data for model validation, [H+] */

2021-03-30T15:24:49Z

‎Data for model validation, [H+]

Avertyshev@mail.ru: /* The rate of muscles glycolysis in general */

2021-03-30T15:23:00Z

‎The rate of muscles glycolysis in general

Avertyshev@mail.ru: /* Data for model validation, [H+] */

2021-03-30T15:21:26Z

‎Data for model validation, [H+]

Avertyshev@mail.ru: /* Data for model validation, [H+] */

2021-03-30T15:21:05Z

‎Data for model validation, [H+]

Avertyshev@mail.ru at 15:20, 30 March 2021

2021-03-30T15:20:16Z

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Avertyshev@mail.ru: Created page with "For model validation, dynamics of activation, ATP, PCr, glycolysis, oxidative phosphorylation. Ver. 1.0. === The rate of muscles ATP hydrolysis === The rate of muscles ATP h..."

2021-03-30T15:08:54Z

Created page with "For model validation, dynamics of activation, ATP, PCr, glycolysis, oxidative phosphorylation. Ver. 1.0. === The rate of muscles ATP hydrolysis === The rate of muscles ATP h..."

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For model validation, dynamics of activation, ATP, PCr, glycolysis, oxidative phosphorylation.
Ver. 1.0.

=== The rate of muscles ATP hydrolysis ===

The rate of muscles ATP hydrolysis with a stepwise increase in external load increases almost immediately (as seen by the rate of ADP formation) (Broxterman et al., 2017 <cite>1</cite>; Bartlett et al., 2020 <cite>2</cite>):

[[File: Bartlett_2020,_Oxidative_ATP_synthesis_in_human_quadriceps_ADP.png | 800px | Changes in ADP (C) across time for each trial]]

Figure from (Bartlett et al., 2020) <cite>2</cite>, Changes in muscle ADP across time during trials.

[[File: Broxterman_2017,_Bioenergetics_and_ATP_Synthesis_during_Exercise.png | 800px | Intramuscular metabolic perturbation during high-intensity intermittent isometric single-leg knee-extensor exercise]]

Figure from (Broxterman et al., 2017) <cite>1</cite>, Changes in muscle ADP across time.

=== The rate of muscles PCr hydrolysis ===

The rate of muscles PCr hydrolysis with a stepwise increase in external load increases almost immediately (Layec et al., 2008 <cite>3</cite>; Cannon et al., 2014 <cite>4</cite>; Fiedler et al., 2016 <cite>5</cite>; Broxterman et al., 2017 <cite>1</cite>; Bartlett et al., 2020 <cite>2</cite>).

[[File: Layec_2008,_Accurate_work-rate_measurements_during_in_vivo_MRS_studies_of_exercising_human_quadriceps_PCr | 800px | Changes in muscle PCr across time]]

Figure from (Layec et al., 2008) <cite>3</cite>, Changes in muscle PCr across time

[[File: Bartlett_2020,_Oxidative_ATP_synthesis_in_human_quadriceps_PCr.png | 800px | Changes in PCr (A) across time for each trial]]

Figure from (Bartlett et al., 2020) <cite>2</cite>, Changes in muscle PCr across time during trials

In tests with a stepwise increase in external load, the following dynamics of changes in the PCr concentration is observed (Schocke et al., 2005 <cite>6</cite>; Greiner et al., 2007 <cite>7</cite>).

[[File: Greiner_2007,_High-energy_phosphate_metabolism_in_the_calf_muscle_of_healthy_humans_PCr.png | 800px | Changes in PCr concentration across time]]

Figure from (Greiner et al., 2007) <cite>7</cite>, changes in the PCr concentration across time

[[File: Schocke_2005,_High-energy_phosphate_metabolism_during_calf_exercise_in_humans_PCr.png | 800px | Changes in PCr concentration across time]]

Figure from (Schocke et al., 2005) <cite>6</cite>, changes in the PCr concentration across time
According to those data, with a frequent stepwise increase or with a gradual increase in external load, the rate of PCr hydrolysis should be constant.

=== The rate of muscles glycolysis in general ===

[[File: Larsen_2014,_High-Intensity_Interval_Training_Alters_ATP_Pathway_Flux_During_Maximal_Muscle_Contractions_in_Humans_Glycolisys.png | 800px | Rates of ATP synthesis during a 24-s maximal voluntary knee extension contraction]]

Figure from (Larsen et al., 2014) <cite>8</cite>, Rates of ATP synthesis during a 24-s maximal voluntary knee extension contraction (MVC), ATP provision from glycolysis (B, ATPGLY).

Calculation of glycolytic ATP synthesis from (Larsen et al., 2014) <cite>8</cite>:

[[File: Larsen_2014,_High-Intensity_Interval_Training_Alters_ATP_Pathway_Flux_During_Maximal_Muscle_Contractions_in_Humans_ Calulations.png | 800px | Calculation of glycolytic ATP synthesis]]

[[File: Layec_2015,_Impact_of_age_on_exercise-induced_ATP_supply_during_supramaximal_plantar_flexion_in_humans.png | 400px | The rate of ATP synthesis through anaerobic glycolysis (A), oxidative phosphorylation (B)]]

Figure from (Layec et al., 2015) <cite>9</cite>, The rate of ATP synthesis through anaerobic glycolysis (A), oxidative phosphorylation (B)

[[File: Walter_1999,_In_vivo_ATP_synthesis_rates_in_single_human_muscles_during_high_intensity_exercise_Glycolysis.png | 800px | Glycogenolytic and glycolytic rates in the medial gastrocnemius during maximal rate exercise]]

Figure from (Walter et al., 1999) <cite>10</cite>, Glycogenolytic and glycolytic rates in the medial gastrocnemius during maximal rate exercise.

Calculation of glycolytic ATP synthesis from (Walter et al., 1999) <cite>10</cite>:

[[File: Walter_1999,_In_vivo_ATP_synthesis_rates_in_single_human_muscles_during_high_intensity_exercise_Calculations.png | 800px | Calculation of glycolytic ATP synthesis]]

=== Dynamics of the activity of some glycolytic enzymes ===

Calcium-regulated PFK-1 activity increases almost instantly (Schmitz et al., 2013) <cite>11</cite>.

[[File: Schmitz_2013,_Combined_in_vivo_and_in_silico_investigations_of_activation_of_glycolysis_in_contracting_skeletal_muscle_PFK.png | 800px | PFK-1 (de)activation kinetics]]

Figure from (Schmitz et al., 2013) <cite>11</cite>, PFK-1 (de)activation kinetics

The PFK-1 activity is regulated by metabolites also

[[File: Schmitz_2013,_Combined_in_vivo_and_in_silico_investigations_of_activation_of_glycolysis_in_contracting_skeletal_muscle_PFK_regulation.png | 600px | The regulation of PFK-1]]

Figure from (Schmitz et al., 2013) <cite>11</cite>, Schematic representation of the regulation of PFK-1 as modeled in each model configuration. Model configuration (B) represented the hypothesis in which binding of calcium-calmodulin complexes to PFK-1 partly reliefs ATP inhibition of the enzyme independent of the levels of ADP and AMP. Model configuration (C) represented the hypothesis in which binding of calcium-calmodulin complexes partly reliefs ATP inhibition by enhancing the competitive binding of AMP and ADP to the inhibitory ATP site.

Glycogen phosphorylase and PDH activity increases within seconds (Parolin et al., 1999) <cite>12</cite>.

[[File: Parolin_1999,_Regulation_of_skeletal_muscle_glycogen_phosphorylase_and_PDH_during_maximal_intermittent_exercise.png | 600px | Regulation of skeletal muscle glycogen phosphorylase and PDH during maximal intermittent exercise]]

Figure from (Parolin et al., 1999) <cite>12</cite>, Regulation of skeletal muscle glycogen phosphorylase and PDH during maximal intermittent exercise.

=== Dynamics of oxidative phosphorylation activity at the onset of exercise ===

Despite the sufficient amount of oxygen bound to myoglobin in the muscles, oxidative phosphorylation begins with some delay with a stepwise increase in load (Grassi et al., 2005 <cite>13</cite>; Richardson et al., 2015 <cite>14</cite>) with a time lag of about 10 seconds.

[[File: Grassi_2005,_Delayed_Metabolic_Activation_of_Oxidative_Phosphorylation_in_Skeletal_Muscle_at_Exercise_Onset.png | 600px | Time courses of changes of deoxygenated Hb + Mb concentration, as well as of oxygenated Hb + Mb concentration]]

Figure from (Grassi et al., 2005) <cite>13</cite>, Time courses of changes of deoxygenated Hb + Mb concentration, as well as of oxygenated Hb + Mb concentration.

[[File: Richardson_2015,_MRS_Evidence_of_Adequate_O2_Supply_in_Human_Skeletal_Muscle_at_the_Onset_of_Exercise.png | 600px | Tracing of the deoxygenated myoglobin (deoxy-Mb) signal at the onset of moderate-intensity exercise]]

Figure from (Richardson et al., 2015) <cite>14</cite>, Tracing of the deoxygenated myoglobin (deoxy-Mb) signal at the onset of moderate-intensity exercise.

During repeated exercise, the oxygen-uptake rate increases faster compared to the first bout of exercise. This must be taken into account when modelling intermittent loads.

[[File: Bangsbo_2001,_ATP_production_and_efficiency_of_human_skeletal_muscle_during_intense_exercise,_effect_of_previous_exercise.png | 600px | Thigh oxygen uptake during EX1 and EX2]]

Figure from (Bangsbo et al., 2001) <cite>15</cite>, Thigh oxygen uptake during EX1 and EX2.

[[File: Combes_2016,_Effect_of_work-rest_cycle_duration_on_VO2_fluctuations_during_intermittent_exercise.png | 600px | VO2 fluctuations for each exercise transition]]

Figure from (Combes et al., 2016) <cite>16</cite>, VO2 fluctuations for each exercise transition

=== Data for model validation, [H+] ===

[[File: Hargreaves_1998,_Muscle_metabolites_and_performance_during_high-intensity,_intermittent_exercise_T2.png | 800px | Table 2]]

Table from (Hargreaves et al., 1998) <cite>17</cite>.

[[File: Hargreaves_1998,_Muscle_metabolites_and_performance_during_high-intensity,_intermittent_exercise_T3.png | 800px | Table 3]]

Table from (Hargreaves et al., 1998) <cite>17</cite>.

[[File: Spriet_1989,_Muscle_glycogenolysis_and_H+_concentration_during_maximal_intermittent_cycling_F1.png | 500px | Schematic representation of experimental design]]
[[File: Spriet_1989,_Muscle_glycogenolysis_and_H+_concentration_during_maximal_intermittent_cycling_T2.png | 800px | Table 2]]

Figure and table from (Spriet et al., 1989) <cite>18</cite>, maximal cycling for 30 s, each separated by 4 min of rest

[[File: Davies_2017,_Dissociating_external_power_from_intramuscular_exercise_intensity_during_intermittent_bilateral_knee-extension_in_humans.png | 1000px | PCr and pH responses to intermittent or continuous exercise]]

Figure from (Davies et al., 2017) <cite>19</cite>, PCr and pH responses to intermittent or continuous exercise.

[[File: Chidnok_2013,_Muscle_metabolic_responses_during_highintensity_intermittent_exercise.png | 600px | Muscle [PCr] and pH responses during high-intensity intermittent exercise]]

Figure from (Chidnok et al., 2013) <cite>20</cite>, Muscle [PCr] and pH responses during high-intensity intermittent exercise.

Overall, MRS studies show pH recovery is too fast compared to studies that used biochemical pH measurements, see below.

[[File: Sahlin_1976,_Lactate_content_and_pH_in_muscle_obtained_after_dynamic_exercise_F2.png | 600px | Relationship between pH and content of lactate + pyruvate in muscle during recovery from exhaustive dynamic exercise]]
[[File: Sahlin_1976,_Lactate_content_and_pH_in_muscle_obtained_after_dynamic_exercise_F3.png | 800px | Time courses of lactate content and pH in muscle samples taken during recovery from exhaustive dynamic exercise]]

Figures from (Sahlin et al., 1976) <cite>21</cite>,

[[File: Parolin_1999,_Regulation_of_skeletal_muscle_glycogen_phosphorylase_and_PDH_during_maximal_intermittent_exercise_T2.png | 800px | Muscle metabolite content in the vastus lateralis at rest and during maximal intermittent isokinetic cycling]]

Table from (Parolin et al., 1999) <cite>12</cite>.

[[File: Parolin_1999,_Regulation_of_skeletal_muscle_glycogen_phosphorylase_and_PDH_during_maximal_intermittent_exercise_F4.png | 800px | Muscle metabolite content in the vastus lateralis at rest and during maximal intermittent isokinetic cycling]]

Figure from (Parolin et al., 1999) <cite>12</cite>.

[[File: Kushmerick_1992,_Regulation_of_oxygen_consumption_in_fast_and_slow-twitch_muscle_F2.png | 800px | The time courses of changes in intracellular pH during stimulation at the various rates for the biceps]]
[[File: Kushmerick_1992,_Regulation_of_oxygen_consumption_in_fast_and_slow-twitch_muscle_F3.png | 800px | The time courses of changes in intracellular pH during stimulation at the various rates for the soleus]]

Figures from (Kushmerick et al., 1992) <cite>12</cite>, Data from cat muscles, The time courses of changes in intracellular pH during stimulation at the various rates for the biceps and for the soleus.

===References===

<biblio>
#1 pmid=28767527 
#2 pmid=32045011 
#3 pmid=18483819 
#4 pmid=25281731 
#5 pmid=27562396 
#6 pmid=15517340 
#7 pmid=17206438 
#8 pmid=24612773 
#9 pmid=26041112 
#10 pmid=10457099 
#11 pmid=23114964 
#12 pmid=10567017 
#13 pmid=16177610 
#14 pmid=25830362 
#15 pmid=11350777 
#16 pmid=26943697 
#17 pmid=9572818 
#18 pmid=2917960 
#19 pmid=28776675 
#20 pmid=24068048 
#21 pmid=13343 
#22 pmid=1415510 
</biblio>

[[Category: Human_muscle]]

← Older revision		Revision as of 15:24, 30 March 2021
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−	[[File: Parolin_1999,_Regulation_of_skeletal_muscle_glycogen_phosphorylase_and_PDH_during_maximal_intermittent_exercise_T2.png \| ~~800px~~ \| Muscle metabolite content in the vastus lateralis at rest and during maximal intermittent isokinetic cycling]]	+	[[File: Parolin_1999,_Regulation_of_skeletal_muscle_glycogen_phosphorylase_and_PDH_during_maximal_intermittent_exercise_T2.png \| 1000px \| Muscle metabolite content in the vastus lateralis at rest and during maximal intermittent isokinetic cycling]]

	Table from (Parolin et al., 1999) <cite>12</cite>.		Table from (Parolin et al., 1999) <cite>12</cite>.

← Older revision		Revision as of 15:23, 30 March 2021
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−	[[File: Walter_1999,_In_vivo_ATP_synthesis_rates_in_single_human_muscles_during_high_intensity_exercise_Calculations.png \| ~~600px~~ \| Calculation of glycolytic ATP synthesis]]	+	[[File: Walter_1999,_In_vivo_ATP_synthesis_rates_in_single_human_muscles_during_high_intensity_exercise_Calculations.png \| 500px \| Calculation of glycolytic ATP synthesis]]
−
−

	=== Dynamics of the activity of some glycolytic enzymes ===		=== Dynamics of the activity of some glycolytic enzymes ===

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 Table from (Hargreaves et al., 1998) <cite>17</cite>.
-[[File: Hargreaves_1998,_Muscle_metabolites_and_performance_during_high-intensity,_intermittent_exercise_T3.png | 600px | Table 3]]
+[[File: Hargreaves_1998,_Muscle_metabolites_and_performance_during_high-intensity,_intermittent_exercise_T3.png | 500px | Table 3]]
 Table from (Hargreaves et al., 1998) <cite>17</cite>.

← Older revision		Revision as of 15:21, 30 March 2021
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−	[[File: Hargreaves_1998,_Muscle_metabolites_and_performance_during_high-intensity,_intermittent_exercise_T2.png \| ~~800px~~ \| Table 2]]	+	[[File: Hargreaves_1998,_Muscle_metabolites_and_performance_during_high-intensity,_intermittent_exercise_T2.png \| 1000px \| Table 2]]

	Table from (Hargreaves et al., 1998) <cite>17</cite>.		Table from (Hargreaves et al., 1998) <cite>17</cite>.

Dynamics of activation - Revision history

Avertyshev@mail.ru: /* Data for model validation, [H+] */

Avertyshev@mail.ru: /* The rate of muscles glycolysis in general */

Avertyshev@mail.ru: /* Data for model validation, [H+] */

Avertyshev@mail.ru: /* Data for model validation, [H+] */

Avertyshev@mail.ru at 15:20, 30 March 2021

Avertyshev@mail.ru: Created page with "For model validation, dynamics of activation, ATP, PCr, glycolysis, oxidative phosphorylation. Ver. 1.0. === The rate of muscles ATP hydrolysis === The rate of muscles ATP h..."