PT  - JOURNAL ARTICLE
AU  - STANLEY J. KOLIS
AU  - MORTON A. SCHWARTZ
AU  - ZANE N. GAUT
AU  - CONSTANCE J. ASHLEY
TI  - THE
<em>IN VITRO</em>
METABOLISM OF 2-HYDROXYNICOTINIC
ACID IN HUMAN ERYTHROCYTES AND PLATELETS
DP  - 1974 Sep 01
TA  - Drug Metabolism and Disposition
PG  - 424--428
VI  - 2
IP  - 5
4099  - http://dmd.aspetjournals.org/content/2/5/424.short
4100  - http://dmd.aspetjournals.org/content/2/5/424.full
SO  - Drug Metab Dispos1974 Sep 01; 2
AB  - The metabolism of 2-hydroxynicotinic acid (2-HNA) was investigated in intact human erythrocytes and platelets and in a phosphate buffer extract of erythrocyte acetone powder. The only metabolite detected on incubation of 2-HNA with the erythrocyte acetone powder preparation was the N-ribotide, 2-HNA-ribose-P. Incubation of 2-HNA with intact erythrocytes or platelets resulted in the formation of the N-riboside, 2-HNA-ribose, which was also formed on incubation of 2-HNA-ribose-P with lysed platelets. Nicotinic acid inhibited 2-HNA metabolism in both the intact cells and in the acetone powder preparation. It is concluded that nicotinic acid mononucleotide phosphoribosyltransferase mediates the conversion of 2-HNA to 2-HNA-ribose-P, and that this intermediate is dephosphorylated to 2-HNA-ribose. This reaction sequence would account for the extensive urinary excretion of 2-HNA-ribose in humans and animals administered 2-HNA. Copyright © 1974 by The American Society for Pharmacology and Experimental Therapeutics