Magnus Lynch wrote:
> When humans evolved their longer lifespans, it may have been easier for
> evolution to change other determinants of metabolic toxicity such as
> respiratory leakiness
I should clarify that "metabolic toxicity" and "respiratory leakiness"
are not standard terminology -- I invented them in a paper that I gave
Magnus a copy of a few weeks ago (J. Anti-Aging Med. 3(1), in press, out
in a month or two). From there:
> It is thus possible to partition the rate of any given process whereby
> oxygen consumption leads to aging into four components (Figure 1):
>> - the specific metabolic rate, or SMR -- the rate of consumption of
> oxygen (essentially equivalent, for aerobic organisms, to that of
> ATP synthesis) per unit mass;
> - the leakiness of that respiration -- the proportion of that oxygen
> which is converted to superoxide;
> - the potency of that superoxide -- the proportion of it which is
> converted to more reactive radicals, rather than being detoxified
> by antioxidant enzymes; and
> - the oxidisability of the tissue -- the propensity of the tissue under
> consideration to suffer oxidation by those more potent species.
>> The combination of an oxidative process's respiratory leakiness,
> superoxide potency and tissue oxidisability will be referred to as its
> metabolic toxicity.
Aubrey de Grey
