Posted by tealady on April 10, 2007, at 5:12:42
In reply to To much Omega 3?, posted by Tom Twilight on April 9, 2007, at 8:02:59
more on thyroid and omega 3 ratio and proton leak rate
Thyroid hormone status and membrane n-3 fatty acid content influence mitochondrial proton leak
Proton leak, as determined by the relationship between respiration rate and membrane potential, was lower in mitochondria from hypothyroid rats compared to euthyroid controls. Moreover, proton leak rates diminished even more when hypothyroid rats were fed a diet containing 5% of the lipid content as n-3 fatty acids. Similarly, proton leak was lower in euthyroid rats fed the 5% n-3 diet compared to one containing only 1% n-3 fatty acids. Lower proton leaks rates were associated with increased inner mitochondrial membrane levels of n-3 fatty acids and a decrease in the ratio of n-6/n-3 fatty acids. This trend was evident in the phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and cardiolipin phospholipid fractions. These results suggest that a significant portion of the effect of thyroid hormone status on proton leak is due to alterations in membrane fatty acid composition, primarily changes in n-3 content. Both the hypothyroid state and dietary effects appear to be mediated in part by inhibition of the Delta6- and Delta5-desaturase pathways.The mechanism of the increase in mitochondrial proton permeability induced by thyroid hormones
The surface area of the mitochondrial inner membrane was shown by three different assays to be greater by a factor of between two and three in mitochondria from hyperthyroid animals than in mitochondria from hypothyroid animals; euthyroid controls were intermediate. This difference in surface area of the inner membrane explains less than half of the difference in apparent proton permeability
The proton permeability of liposomes prepared from phospholipids extracted from mitochondrial inner membranes of hyperthyroid rats was three times greater than the proton permeability of those from hypothyroid rats; euthyroid controls were intermediate.
first, that the proton permeability of the phospholipid bilayer is an important component of the proton permeability in intact mitochondria and, second, thyroid hormone-induced changes in the bilayer are a major part of the mechanism of increased proton permeability. Such changes may be due to the known differences in fatty acid composition of mitochondrial phospholipids in different thyroid states. Thus we have identified two mechanisms by which thyroid hormone levels in rats change proton flux/mass protein in isolated liver mitochondria: a change in the area of the inner membrane/mass protein and a change in the intrinsic permeability of the phospholipid bilayer
This is why I am worse on fish oils when hypo(TSH over 3)...Think I also had stuff on light (length of day, perhaps intensity if memory is correct) altering fatty acid levels as well as VitD ..
unsure of heat if anything been studied.. but it sure seems to fit from my observation..just a bit on why NOT to OD on fish oil :-)
like I said, probably fine if you live in canada, Norway, Alaska etc.. and not too hypo (tired and depressed main symptoms with added anxiety)
poster:tealady
thread:748352
URL: http://www.dr-bob.org/babble/alter/20070410/msgs/748673.html