Effect of maternal vitamin B-6 restriction on pyridoxal phosphate concentrations in developing regions of the central nervous system in rats.

The effect of maternal vitamin B-6 deficiency on concentrations of pyridoxal phosphate (PLP) within four different regions of the central nervous system (CNS) of progeny, the corpus striatum (CS), hypothalamus (H), cerebellum (C), total brain and first cervical segment (C-1) of the spinal cord was determined at 7, 15, 21 and 50 days of age. PLP concentrations in each CNS region, as well as in total brain at 15, 21 and 50 days postnatally, paralleled the level of vitamin B-6 in the deficient (0.6, 0.8, 1.0 mg pyridoxine . HCl per kilogram diet) and control diets (7.0 mg pyridoxine . HCl per kilogram diet). By 21 days of age, PLP concentrations had essentially plateaued in CNS regions of controls, whereas in the vitamin B-6-restricted groups, a significant catch-up in concentration was observed between 21 and 50 days of age in all CNS regions except C-1 of the spinal cord. Throughout postnatal development, PLP concentrations in the C-1 region of spinal cord and in hypothalamus appeared least affected by vitamin B-6 restriction and levels in CS and C were most affected. These findings suggested that the mechanism for intracellular trapping of B-6 vitamers may develop in a caudal to rostral direction within the CNS.