Free Radicals, more constraints

Edward Krug kruged at ESSEX.HSC.COLORADO.EDU
Tue Jan 31 01:05:56 EST 1995

On 30 Jan 1995, Michael J. Conboy put forward the question of whether 
cells actually need and/or use free radicals, and that they are not be 
eliminated at all cost. (my gross editing, ed).

Much of the biochemistry of life consists of passing along unpaired 
electrons, involving everything from the killing of microorganisms to 
basic mitochondrial function.  By definition, "a Free Radical is any 
molecule that has an odd number of electrons".	I pulled some journal 
review articles on free radicals and shocked myself at seeing how many 
normal metabolic processes generate free radicals.  I had thought that 
talking about free radicals in general terms was too symplistic, but fear 
that it is even worse than that.  The number and types of free radical 
sources and they diversity of damages they can generate are 
sufficiently large that a shopping list of antioxidants need be 
generated.  One article pointed out that some scavangers at higher 
concentrations can affect the normal enzymes (CuZn-superoxide 
dismutase, and a number of other enzymes) used to scavange 
hydrogen peroxide or the O2- radical.  It can be possible to have too 
much of some of the antioxiedes, so I suspect that the shopping list of 
antioxidants need include some form of a "minimum daily requirement" 
indication, and probably a maximum as well.  This list will have to be a 
living list, growing as more is discovered, such as the agents used to 
inhibit non-enzymatic addition of sugars to lipids and proteins in the 
process of "browning" or non-enzymatic glycalation.  This is the source 
of much of the tissue damage occuring in diabetics, and possibly the lack 
of this type of damage in the caloric restricted diets may contribute to 
the diets success.

Conclusion??  Does anyone know if a list of recomended antioxidants with 
doses which goes beyond the simple list, to include such things as 
aminoguanidine hydrochloride (25 mg/mk, New Eng. J. of Med, 1988, vol 
318, pp 1315-1321)?

Edward C. Krug Ph.D.  E-mail= kruged at essex.hsc.colorado.edu
303-270-7234 (vox), 303-270-8681 (fax) Univ. of Colorado Med. School

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