Influence of Pyridoxine on Transaminase Activity of Human Placenta, Maternal and Fetal Blood.

Abstract

The glutamic-aspartic transaminase activity of whole blood from normal pregnant subjects is essentially the same as in non-pregnant subjects (means, 734 and 748 [mu]l oxalacetate/hours/ml, respectively). Activity is significantly increased (to 984 [mu]l) by supplementing the diet with 10 mg of pyridoxine daily for 4-6 weeks. Transaminase activity of fetal blood is twice as great as in maternal blood in mothers not receiving additional B6. Transaminase of term placenta (mean QT10, 37.9 [mu]l) is not altered by prior administration of pyridoxine for several weeks. The activity in term placenta is considerably higher than that in fetal cord blood when the latter is expressed in units per mg dry weight. Results suggest that fetal tissues contain optimal quantities of Bg, whereas adults, both pregnant and non-pregnant, contain suboptimal concentrations for peak enzymatic activity. Data are compatible with the view that pyridoxine supplementation is desirable in human pregnancy.