Effects of Pregnancy and Lactation on Pyridoxal 5′-Phosphate in Plasma, Blood and Liver of Rats Fed Three Levels of Vitamin B-6

Publisher Website
Google Scholar
Abstract
Male, virgin female and 2-day timed pregnant female rats were fed diets containing 0.29, 20.2 and 1,430 mg vitamin B-6 per kilogram of diet. After 6 weeks, adult rats and pups were killed and the concentration of pyridoxal 5′-phosphate (PLP) in the plasma was measured. Regardless of diet, the concentration of PLP in plasma of dams was greatly depressed when compared to the concentration in males and virgin females. Massive amounts of vitamin B-6 in the diet did not overcome the effect. Other dams were fed the three diets, then killed at certain times during pregnancy and lactation. The concentrations of PLP in plasma, whole blood and liver were measured. For dams receiving the vitamin B-6-adequate and high vitamin B-6 diet, the plasma PLP concentration increased after 1 week of pregnancy, decreased to a low point on the day of delivery and remained low during lactation. The PLP concentration of whole blood showed a similar pattern. The PLP concentration did not change as dramatically in liver as in plasma or whole blood. There was little difference between the plasma PLP concentration of dams fed the vitamin B-6-adequate or the high vitamin B-6 diet. Whole blood PLP was a better indicator of vitamin B-6 intake for pregnant and lactating rats than was plasma PLP.