RE: origins of endothermy

[Jeffrey Martz <jeffmartz@earthlink.net>]

A few more words on decoupling oxidative phosphorylation from electron 
transport from my animal physiology text...

      "...oxidative phosphorylation becomes uncoupled from electron transport 
_whenever something happens_ that makes the mitochondrial inner membrane 
"leaky".'  
      It goes on to say that in cases of the membrane being broken or the 
mebrane somehow becomes more permiable to H+ ions, ATP production is dropped 
while electron transport and reduction of O2 to H2O, accompanied by heat 
production, continues.  It seems to imply that this is something that can 
happen to ANY cell that is damaged or changes permiability for some other 
reason, not just as part as the regular functioning of brown fat.  
      It doesn't mention if uncoupling proteins are used, although I assume 
they are.  Nor does it say which groups of animals this applies to.  However, 
the references I mentioned before note that both birds and mammals seem to have 
leakier cell membranes then ectotherms, so I'm guessing the process I just 
describes works the same for both, and isn't neccessarily restricted to brown 
fat (which birds do not have).

LN Jeff