Intense Exercise- Reduced ATP/ PCr and Increased Pi W2 Flashcards
What does ATP concentration never drop below?
60%
What may ATP decline from?
24mM to 12mM
What may ADP increase from?
10 to 200uM
Why might be there localised ATP depletion in the space between the T-Tubule and the SR?
Due to ATP consumption in this region being substantial
How does the triad junction play a key role in sensing ATP depletion in HIE?
Reduces Ca2+ release to decrease the rate of usage on ATP
What are the 2 main sources of ATP hydrolysis?
Crossbridge cycling
SR Ca2+ uptake
What may PCr decline from?
80 to 15mM
What dissociation is there when considering PCr during HIT?
Rate of recovery PCr and force-generating capacity of the muscle
What has a faster recovery time, PCr or muscle force?
PCr recovery
What catalyses the exchange between ATP and PCr?
Creatine Kinase
What happens to PCr during high energy demands?
It breaks down into Cr and Pi
What may Pi decrease?
Myofibrillar force production
Ca2+ sensitivity
SR Ca2+ Release
How does increased Pi inhibit force production?
Has direct action crossbridge functions
What force does Pi decrease?
Tetanic fore during fatigue in type IIx fibres
