The effect of a long-term excess of pyridoxine on the fatty acid composition of the major phospholipids in the rat.

The effect of a long-term excess of pyridoxine on the fatty acid spectrum of phosphatidylcholine, lysophosphatidylcholine and phosphatidylethanolamine of liver, plasma and kidneys in rats was studied to determine whether this response might be opposite to that observed during a deficiency. As a function of time, the fatty acid composition of the phospholipids generally changed similarly in both the control group and the pyridoxine-treated group. Though differences did occur between the two groups, particularly on day 14 of the treatment, they generally disappeared by day 22. We therefore attributed the major part of the changes occurring in the pyridoxine-treated rats to the age or development of the rats rather than to the pyridoxine treatment itself. In general, the proportion of arachidonic acid increased with time in the phospholipids of both groups while that of linoleic acid decreased. The magnitude of these changes and the proportion of the different fatty acids in the various phospholipids were not uniform from one phospholipid to another or from one tissue to another. Possible mechanism were discussed.