Muscle and Exercise Lecture 3.2 - Muscle wasting conditions: a shift in the balance Flashcards
Name 3 muscle wasting conditions. What is the driver behind them?
Cancer cachexia
Sepsis
Sarcopenia
Inflammation is a driver in all of them.
What is characteristic of sarcopenia? What percentage of muscle mass is lost?
Loss of muscle and increase in fat.
50% muscle mass loss.
Is protein synthesis decrease the sole cause of sarcopenia?
No, protein synthesis does decrease, not sole cause.
What are some factors contributing to sarcopenia (name 4)?
Poor nutrition, diseased state, neuronal input loss, and age.
Is there a difference in basal protein synthesis rates in young vs old people?
No, theyre the dame.
What happens to protein synthesis after eating protein?
Increases for several hours after eating.
What is one’s protein balance like throughout the day?
ON average it is 0, but is in the positive and negative throughout the day. Averages to 0.
How do old people respond to resistance training with increasing protein synthesis vs young people? What is the actual difference like?
Young people respond well, but old people less well.
Actual difference is quite small.
What is a problem with sepsis, bedridden and ICU patients regarding food intake?
They can’t tolerate a lot of food intake, problem as they need protein to maintain protein turnover.
What are glucose levels like in bedridden/ICU patients?
Hyperglycaemic.
What is high muscle mass loss in ICU patients associated with?
Multiple organ failure.
How can you induce inflammation in mice?
Inject bacterial Lipopolysaccharide (LPS).
Signal cascade causes inflammation agent release.
Does inflammation stimulate protein breakdown pathways? What happens to protein synthesis and drive to eat (with PLS injection)?
No, it didn’t. But protein synthesis decreased 40-50%.
Drive to eat was gone.
What do tumours release in cancer cachexia? Wha is a consequence of this?
Inflammatory factors, causing systemic apoptosis. Causes muscle mass loss and metabolsim change.
What two resources do tumours rely heavily on (one amino acid)?
Glutamate and glocuse.
