What is the rate of decay of lactate in a cell?

[Maria87]

Hi All,

Does anyone know (or have a reference) the rate of decay of lactate (biological half-life) in a normal functioning cell ? I've looked in many places but could only find during exercise or shock.

PS: I know that lacate can be used as fuel for energy. Is there any other usage of lactate in a cell?

Please help.

Many thanks

[Pammy]

Not sure about the timescales, and I guess that would depend on many factors!
But as for fates of lactate:
(1) As fuel, by oxidation (lactate then pyruvate then acetyl-CoA and TCA cycle etc)
(2) As precursor for gluconeogenesis (via pyruvate, OAA, PEP)
(3) Signalling molecule, e.g. when lactate builds up at high exercise intensities (above the lactate threshold, around 85% VO2max but of course that depends on the person) it can actually signal to adipocytes to suppress lipolysis. That's speculated to be part of the reason why high exercise intensities can't be supported by oxidation of fat, you need CHO.

Hope that helps!