Exercise & Innate Immune Function Flashcards
What did hack et al suggest the mechanism that effects respiratory burst depend on exercise intensity is ?
Adrenaline
This is because the adrenalin suppressed neutrophil function which increased cAMP, thus inhibiting signaling pathways associated with superoxide production, degranulation, chemotaxis and phagocytosis.
What is the chronic training effect on NK cell numbers and NKCT (natural killer cytotoxic activity) ?
NK cell number and NKCT per cell are significantly higher in people who undergo regular endurance training.
However during a period of very high intensity training the NK number will decrease.
What is the effect of strenuous exercise on rates of chemotaxis and how does this happen ?
Strenuous exercise impairs chemotaxis
it does this as as it reduces the ability of the cells to adhere to the membrane.
Secondly strenuous exercise resulted in a reduction of cell migration through via diapedesis (moving through membrane gaps).
Both of these are still significantly reduced 24 hours later.
From the information given in the prior study mentioned by Davies where they investigated survival rates and macrophage function in mice, why might the knowledge of exercise effect on TLR’s expand thee findings ?
The survival rate in the mice likely dropped significantly in the exhaustive trial because there TLR were significantly impaired, allowing greater virus replication leading to death.
During exercise why is there an initial increase in leucocyte overall leucocyte amount.
Initial increase as the cells that are normally resting on the vessel walls are pulled into circulation in a process called demargination, caused by increased shear stress by heightened blood flow and reduced adherence via adhesion molecules due to adrenalin.
It is worth remembering that the overall increase during exercise is dependent on both the intensity and the duration.
How do NK cell numbers and the Cytotoxic ability (killing ability) differ to the other immune cells post exercise?
Like others immune cells the NK number increases post exercise due to demargination then drops of due to adrenalin being removed and cortisol simulating removal from circulation.
This is also true for the overall Cytotoxic ability of NK cells which follow the trend.
However, If you look at the cytotoxic ability of each NK cell individually there is actually an upwards rise following exercise.
How did the hack paper assess respiratory burst via the production of what free radicle ?
O2
What did Ceddia and Woods, 1999, show about the levels of antigen presentation in mice following moderate, exhaustive and an ad lib treadmill controls ?
In moderate exercise macrophage AP was elevate immediately, but significantly reduce 4 hours post, However this rebounded to a significant increase 24 hours later.
Comparatively in exhaustive exercise this was AP was significantly reduced immediately post and at three hours post. But unlike moderate exercise it did not rebound and was still significantly reduce compare to a control, indicating the immune systems inability to perform properly, likely due to the TLR expression being reduced.
What are the mechanism underlying the initial and delayed increases in neutrophil counts in exercises ?
Initial - Adrenalin and demargination
Delayed increase - Cortisol stimulating release of neutrophils from bone marrow.
Cortisol makes lymphocytes and monocytes leave circulation but increases neutrophil counts.
How did Smith et al (1990) further the work of hack in regards the the effect of moderate and intense training effect on respiratory burst levels ?
Moderate training increases the burst response for 6 hours post exercise, whereas similarly to hack et al, higher intensity sustained training damped it down at rest, post and 6+ hours.
What is the major influencer of NK cell function and who reported this ?
Adrenalin in the Major influencer of NK function.
This was reported by Kappel et al., 1991 who found that by measuring exercise adrenalin levels and then on a separate day infusing adrenalin to this same level the NK cell function responses were almost identical.
This is because NK cells have greater numbers of Adrenal receptors (Beta 2 type)
How were the findings on adrenalin and its effect on NK function expanded by Fletcher and Bishop, 2012 study using caffeine ?
Using caffeine supplementation the NK cell number was significantly higher post exercise. At this time was also when the adrenalin has spiked.
In Hack, what was the effect of acute exercise on respiratory burst activity in MT and IT vs control groups?
Acute exercise caused an earlier decrease in Respiratory burst, happening immediately post exercise in MT and IT compared with 30mins later in the control.
Moreover, in all groups there is a super compensation response 24 hours post exercise.
However, in the IT group all of the values were dampened down, as seen with other results from IT training bouts.
What are the three main functional activities of a neutrophil ?
Phagocytosis ( engulf )
Respiratory burst ( release of free radicles)
Degranulation (release of cytotoxic enzymes )
What did bishop et al ., 2003 show about the cause for reduced neutrophil degranulation and function?
Bishop showed that with exercise there is an standard expected increase in neutrophil released elastase counts in circulation.
However, the induvial release per cell is lower and is likely caused by interruption of stimulating pathways and elastase release is reduced.
