Effect of pyridoxine deficiency on immunological phenomena.

Measurements of serine hydroxymethyltransferase (SHMT) in resting lymphocyte cultures showed that the level of activity of this enzyme was very low. Under the influence of mitogenic stimuli serine hydroxymethyl-transferase activity was induced 5-20-fold. Addition in the cultures of 4-deoxypyridoxine, a potent antagonist of vitamin B6 coenzymes, concurrently with the mitogen, inhibits the induction of serine hydroxymethyltransferase.

Inhibitory effect of deoxypyridoxine on the action of certain mitogenic factors.

We studied the effect of pyridoxine deficiency state on the responses of human lymphocytes to certain mitogenic factors. Deoxypyridoxine (DB6), a potent pyridoxine antagonist, considerably inhibited Bromodeoxyuridine (BrdU) incorporation into the newly synthesized DNA of lymphocytes cultured with Phytohemagglutinin (PHA) and Concanavalin A (Con A) in separate sets of experiments. The addition of deoxypyridoxine simultaneously with or few hours prior to initiation of cell cultures did not significantly alter the inhibitory action of deoxypyridoxine.