USE OF HIGH PERFORMANCE LIQUID CHROMATOGRAPHY TO STUDY ABSORPTION AND METABOLISM OF PURINES BY RAT JEJUNUM IN VITRO

¹ Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU

A simple and specific analytical method incorporating high performance (anion-exchange) liquid chromatography has been used to study the absorption and metabolism of some purine derivatives in an in vitro preparation of adult rat jejunum. When present in the lumen the purine bases guanine (4 x 10^-5 M), hypoxanthine or xanthine (10^-4-3 x 10^-4 M) do not appear in the serosal secretions but the uric acid (UA) content of these secretions is increased. With UA in the intestinal lumen (10^-4-3 x 10^-4 M) the serosal UA is increased, in some cases to a higher concentration than that in the lumen. With adenine in the lumen (10^-4-10^-3 M) there is an increased appearance of UA and adenine also appears in the serosal secretions, but the concentration of adenine never exceeds that in the lumen.

It is concluded that purines absorbed from the lumen are significantly metabolized to UA during translocation across rat jejunum. Negligible amounts of metabolites are found in the luminal solutions except for guanine which appears to be degraded in the lumen.