QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Boxer, G. E. Articles by Goodhart, R. S. Search for Related Content PubMed PubMed Citation Articles by Boxer, G. E. Articles by Goodhart, R. S.

Pyridoxal-5-Phosphoric Acid in Whole Blood and Isolated Leukocytes of Man and Animals

Merck Institute for Therapeutic Research, Rahway, N. J. and the Bureau of Nutrition, Department of Health, City of New York, N. Y.

Methods are described for the determination of pyridoxal-5-phosphoric acid (B₆-PO₄), codecarboxylase, in whole blood and in isolated leukocytes.

While B₆-PO₄ is measurable in the blood of most animal species investigated, levels below the detection limit, i.e., less than 10 mµg/ml are found in over 80% of adult humans. Children up to about 18 months of age show readily measurable B₆-PO₄ levels in whole blood. Oral feeding of any form of vitamin B₆ leads to a prompt rise in whole blood B₆-PO₄ in man, but a saturation level of about 60 mµg/ml is reached on feeding 4 to 7 mg of vitamin B₆.

The B₆-PO₄ content of leukocytes can be readily measured in the leukocytes isolated from 5 to 10 ml of human blood. In two large groups of adults an average of 0.15 ± 0.07 mµg of B₆-PO₄ per 10⁶ leukocytes has been found. A significantly higher value was found in a group of New York school children (11 to 12 years) indicating the possibility of regression of leukocyte B₆-PO₄ with age. A sample of Cuban school children of the same age group showed even higher leukocyte B₆-PO₄ figures and the possible significance in terms of diet is discussed.

A high percentage of very low leukocyte B₆-PO₄ values was found in a small group of arteriosclerotic patients. Additional data will be required to establish correlation between this finding and clinical observations.