Paul Brookes wrote:
> I disagree that because there isn't much 22:6n3 doesn't mean its not
> important. ... Far better to use a more generic parameter like
> unsaturation index, or better still to look at each lipid individually.
Certainly -- I didn't mean to imply that it didn't matter at all, only
that a membrane can in principle have more 22:6 but be less oxidisable.
Pamplona 1996 did exactly as you say: they have a table of 14 individual
fatty acids and also computed the unsaturation index, which was 3.5 for
rats and 3.1 for pigeons. The peroxidisability index is an even better
number if we want to test the idea that peroxidation causes leak, and
it's even more dramatic -- 97.8 for rats and 67.4 for pigeons. If we
bear in mind that pigeons have about twice rats' specific metabolic rate,
this is quite a challenge to Skulachev's proposal.
Aubrey de Grey