Interaction between vitamin B6 deficiency and low EFA dietary intake on kidney phospholipids and PGE2 in the rat.

Vitamin B6 is involved in the metabolism of long chain polyunsaturated fatty acids and phospholipids. We have studied the interaction between pyridoxine deficiency and low amounts of dietary essential fatty acids (EFA) in the rat. The fatty acid composition of kidney phospholipids of pyridoxine deficient animals shows a decrease of 20:3 n9 and an increase of 20:4 n6 in comparison with control and pair fed animals. This variation of fatty acid composition could be due to the simultaneous effect of vitamin B6 deficiency, which reduces the oxidation of linolenate, and of a low intake of EFAs which stimulates delta-6-desaturase. The dietary treatment also influences kidney Prostaglandin E2 (PGE2) levels which are higher in vitamin B6 deficient animals. This effect could be correlated with a higher response to sympathetic stimulation caused by the simultaneous presence of vitamin B6 deficiency and low EFA availability. Also the higher level of arachidonate could be involved in promoting PGE2 synthesis.