From Wiki: "High levels of purines [like uridine] are known to increase uric acid production and may aggravate or lead to conditions such as gout." Lower purine diets recommended for those sensitive to kidney stones: http://www.litholink...DietInformation
I don't think uridine is a purine. It doesn't have the fused ring structure, and all the articles I just read talk about purines and uridine as different classes. Uridine and cytidine are pyrimidine nucleosides. So I don't think it's going to be changed directly into uric acid, though my chemistry is pretty weak and I could be quite wrong about that.
Various purines are degraded to uric acid via several pathways; see these two graphics for examples [
1] [
2], and see these pages for some good discussions on purine biochemistry [
3] [
4]. Uridine does not appear to have a direct impact on purine degradation, that I could find with an hour's searching.
However, uridine is capable of stimulating ATP release [
5], probably via P2 receptors [
6], but ATP may also be consumed by the Uridine-UDP cycle [
7]. ATP appears to be the primary link between the metabolism of puridines and pyrimidines [7]: it is required for the biosynthesis of several purine nucleotides [4], and itself contains the purine base adenine [3]. ATP depletion appears to increase purine degradation [
8], and an increase of puridine degradation may increase uridine levels by inducing pyrimidine degradation (breakdown of UTP to uridine) [
9].
So that brings us to this finding:
Metabolism.' class='bbc_url' title='External link' rel='nofollow external'>http://www.ncbi.nlm.nih.gov/pubmed/9225835']Metabolism. 1997 Jul;46(7):801-4.
Is the plasma uridine level a marker of the overproduction of uric acid?
Yamamoto T, Moriwaki Y, Takahashi S, Tsutsumi Z, Yamakita J, Higashino K.
To determine whether the plasma level of uridine can be used to identify patients with gout, the plasma concentration of uridine was determined in patients with gout and normal subjects. Plasma uridine was significantly higher in patients with gout than in normal subjects. It was also significantly higher in patients with gout of the overexcretion (of uric acid) type than in those with gout of the underexcretion type. Plasma uridine was used to classify gout patients into underexcretion and overexcretion types, with a diagnostic accuracy of 92.5%. Results indicate that the plasma uridine concentration may be a marker of uric acid production and can be used to separate hyperuricemia into the overexcretion and underexcretion types.
→ source (external link)
This uridine/purine degradation correlation also exists in other models, like exercise [
10] [
11]. The last few references in the previous paragraph suggest that increased uridine may be a
downstream effect of increased uric acid. However, these pyrimidine and purine pathways are linked in several different interconnected cycles of synthesis, degradation, and resalvage (i.e. a damn headache). Given the data I could find this morning, I'm unable to say whether this putative cause/effect relationship is strictly unidirectional (i.e. whether supraphysiological levels of uridine from supplementation might increase purine synthesis or degradation).
There are several genetic risk factors for gout, so if you suspect you carry any of these, it might be wise not to play with your uridine levels. Otherwise, I'm not sure. Personally, I'm a little uncomfortable tinkering with all the basic metabolic processes uridine seems involved with. If I end up taking this long-term or recommending it to family members, it will probably be in pretty low doses. Lots of other fish in the neurogenic and dopaminergic seas...
Edited by chrono, 23 November 2011 - 04:26 PM.
LongeCity
