Andy <ricyoung at iupui.edu> wrote (7664, Sun, 11 Apr 1999):
>To whoever posted the orginal:
The original posting wasn't mine, but I'll answer anyway.
>has uric acid been demonstrated to have an inverse relationship to
>immunochemokines in general?
Not to my knowledge - that is, I do not know of any demonstrated inverse
relationship with prostaglandins and leukotrienes. Reactive oxygen
species are a different matter however. It is as effective an antioxidant
as ascorbate (vitamin C) and it makes a major contribution to assays of
radical trapping potential (Whitehead et al., Anal. Chim. Acta, 1992, 266,
265). As its plasma concentration is considerably higher than that of
ascorbate, it has to be considered one of the major antioxidants in
humans. Indeed, it has been proposed as a major factor in lengthening
life-span and decreasing age-specific cancer rates during primate
evolution (Ames et al., Proc. Nat. Acad. Sci. USA, 1981, 78(11), 6858).
As to its putative negative association with multiple sclerosis, the
following additional facts, which I believe to be established (sorry,
Frank, no references), support this relationship.
(1) 60% of multiple sclerosis patients are female; females have a lower
mean urate level than males.
(2) It has been suggested (Whitehead et al.) that serum urate levels
possibly increase with age; risk of onset of multiple sclerosis reduces
with age during adult life.
There is evidence of increased lipid peroxidation in multiple sclerosis
patients, but what I know of is not very powerful evidence (Naidoo and
Knapp, Clin. Chem., 1992, 38, 2449 - positive in serum but negative in
cerebro-spinal fluid). I am still puzzled about the absence of reports
that levels of other antioxidants are depleted in multiple sclerosis.
Does anyone know of any, please? Does anyone know of any other studies of
antioxidant levels in MS, whether the results were positive or negative?
If other antioxidants are not depleted, it suggests that the protective
effect of hyperuricaemia - if it is real - is due to some *special* effect
of uric acid and not due to its antioxidant properties.
Dr. Alan Wheatley at http://www.canadalane.demon.co.uk