Pyridoxine-5'-beta-D-glucoside influences the short-term metabolic utilization of pyridoxine in rats.
This study was conducted to characterize the initial time course of the apparent competitive effect of pyridoxine-5'-beta-D-glucoside against co-ingested pyridoxine. Two groups of rats were administered a single oral dose of 100 nmol of [14C]pyridoxine along with either 0 or 20 nmol of unlabeled pyridoxine-5'-beta-D-glucoside. At 6, 12, 24 and 48 h post-dose, the distribution of labeled vitamin B-6 metabolites in blood, tissues and urine was determined. Urinary [14C]4-pyridoxic acid comprised a significantly greater percentage of excreted 14C in the control group, with the greatest difference at 12 h post-dose. Pyridoxine-5'-beta-D-glucoside (10-15 nmol) was excreted mainly in unchanged form within 6 h. Rats that received pyridoxine-5'-beta-D-glucoside retained less 14C in liver, with a maximal difference between groups at 6-12 h post-dose. The relative concentrations of hepatic [14C]pyridoxal 5'-phosphate and [14C]pyridoxamine 5'-phosphate in the treatment group were greater than in the control group at approximately 12 h post-dose. At 48 h post-dose, there was no difference in the distribution of any vitamin B-6 metabolite except pyridoxal 5'-phosphate in the two groups. These results confirm that a small, nutritionally relevant dose of pyridoxine-5'-beta-D-glucoside influences the utilization of pyridoxine and indicate that this is a short-term, transient effect.
Nakano
H
H
Food Science and Human Nutrition Department, University of Florida, Gainesville 32611-0370, USA.
Gregory
J F
JF
D000818:Animals; D002250:Carbon Radioisotopes; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005960:Glucosides; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000737:chemistry; D008297:Male; D011736:Pyridoxine / Q000031:analogs & derivatives* / Q000032:analysis / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014018:Tissue Distribution
D002250:Carbon Radioisotopes; D005960:Glucosides; C022945:5'-O-(glucopyranosyl)pyridoxine; D011736:Pyridoxine