The statement in the Overview paragraph that nucleotides and their bases are not required dietary components may be open to question.
The work of Dr. Charles Van Buren at the
University of Texas Medical School , Department of Organ
Transplantation, who has been involved in immunosuppresion
research for over 15 years, His findings "...initially suggested in the observation
that renal allograft patients supported with parenteral
nucleotide-free nutrient solutions displayed a suppressed
immune response to the allograft despite reduction in
pharmacoimmunosuppression" show that in immunosuppresion
patients dietary pyrimidines (uracil) and not purines
(adenine) have a significant effect on the T-lymphocyte
function. He has, in recent years also had an opportunity to
conduct some research using human subjects, who were
hospitalized and immunosuppressed due to transplantations
and therefore well controlled, and produced similar results
to his initial lab research.
Dismissal of the necessity of a dietary source in the first paragraph
and then the somewhat detailed description of their
metabolism in the "Hydrolysis of Polynucleotides" section may seem to be somewhat incongruous unless there is
some question as to whether or not they might
be necessary.
Further, the statement that "little dietary purine is used
and that which is absorbed is largely catabolized," leaves a
question of what use is the little that isn't
catabolized ? Also, purines and pyrimidines from tissue
turnover which are not salvaged are catabolized and
excreted and the fact that de novo synthesis is rather
energy intensive could suggest that dietary sources,
when available, would be welcome additions to metabolism
mechanisms. And what of hepatic tissue of deficient and
diseased patients? Can they survive solely through salvage
methods alone? And as we age does not the ability to produce
needed nucleic acids decrease?
Van Buren C.T., Kulkarni A.D., Schandle V.B., "The
Influence of Dietary Nucleotides on Cell-Mediated Immnity",
Transplantation 1983, 36:350-352
Van Buren C.T., Kulkarni A.D.. Rudolph F.B., "The Role
of Dietary Nucleotides in Adult Nutrition", The Journal of
Nutrition, January 1994; 124:124S-160S.
Return to the main Purines and Pyrimidines page.