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12. Appendix C–Cell Lysing
Obtaining reliable results that have value requires a basic understanding of what
is going on inside the whole blood sample, at least as it relates to lactate.
Lactate is always present in the blood plasma at some level due to minor
anaerobic activity. As the consumption of free oxygen increases during exercise,
anaerobic activity increases, and so does the lactate concentration.
Lactate production starts inside the muscle cell, and the lactate then diffuses
through the cell wall into the blood cell carrier fluid, plasma. The plasma lactate
will then in turn diffuse through the red blood cell walls in order to achieve an
equilibrated state. It takes several minutes for this to happen. As a result,
depending at which point in an exercise the whole blood sample is taken, the
concentration of plasma lactate (extracellular), may be significantly different
than the concentration of lactate in the red blood cell (intracellular).
For example if the sampling was done very early, the equilibration of the plasma
lactate and the cell lactate will not have taken place yet and the plasma lactate
concentration will be higher. Conversely, if the sampling was done much later,
the lactate concentrations will be much closer or equal.
In a non non non non----lysing system lysing system lysing system lysing system the blood cell walls create a barrier that the intracellular
lactate can "hide behind". When a blood sample is injected into the sample
chamber, the extracellular lactate dilutes into the buffer solution immediately.
The intracellular lactate does not however due to the time required to diffuse
through the cell walls. Given sufficient time the lactate would diffuse through
the cell walls and then dilute into the buffer solution allowing all of the the
lactate to be measured. This is not practical however as the rate at which this
diffusion would take place would severely lengthen the duration of each
measurement cycle. Therefore the only lactate that can be measured on a
Therefore the only lactate that can be measured on a Therefore the only lactate that can be measured on a Therefore the only lactate that can be measured on a
SPORT in a non
SPORT in a non SPORT in a non
SPORT in a non----lysing system is extracellular.
lysing system is extracellular. lysing system is extracellular.
lysing system is extracellular.
What this means quite simply is that without a way of assuring that the cell
walls have been removed when we do a sample measurement, we can never
expect to get a true TOTAL LACTATE
TOTAL LACTATE TOTAL LACTATE TOTAL LACTATE reading on the SPORT
This can be done by introducing certain chemicals into the buffer solution inside
the sample chamber that effectively tear apart the cell walls of the blood sample
immediately upon contact. This allows both the intracellular and extracelleular
lactate to dilute immediately into the buffer solution, and because preservatives
now can access the contents of the cell, any additional lactate production is
prevented within the sample.
Another variable that plays a significant role in the lactate equation is how the
sample is cared for prior to measurement. If the sample is exposed to elevated
temperatures before measurement it is quite likely that additional lactate
production will continue within the unlysed blood cells. This can add to the