Aubrey de Grey wrote:>>>>>>>>>>>>>>>
Since (if I understand it) Richard's model involves a potential difference
between regions that are connected by a virtually perfect conductor (the
cytosol), I have difficulty seeing how Guy can be wrong that the influx of
cations at the plasma membrane raises the potential at the mitochondrial
membrane. But the inference that the mitochondrial delta-psi oscillates
by an amount similar to that at the plasma membrane may be wrong, if there
is a very rapid compensatory response that imports cations into the matrix.
I am currently rather enamoured of the ATP- (and also GTP-, GDP- and more)
sensitive potassium channel, which has been strongly implicated in the
homeostasis of mitochondrial volume (an important regulator of OXPHOS); it
also seems to stabilise delta-p, by adjusting the contributions of delta-pH
and delta-psi in response to changing cytosolic cation concentrations.
Czyz et al. 1995, BBRC 210:98-104 has details. Might it be involved here?
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No, because mitochondria do not "feel" action potential at all. If you are
in a metal cage at high voltage, what would you (or your mitochondria)
feel? You can touch the cage - nothing. Guy could only be right if the
cytoplasm far from the membrane became positively charged, i.e. if the
excess charge were not restricted to an extremely narrow area at the membrane
but rather distributed uniformely in the bulk phase. Very few people
(if any) would accept such a claim.
Pentcho Valev
