Differential transplacental binding of valproic acid: influence of free fatty acids.
The unbound fraction of valproic acid (VPA) was found to be significantly lower in cord serum (6.0 +/- 0.8%) than in maternal serum collected before oxytocin (12.2 +/- 2.7%) or after delivery (9.9 +/- 2.3%). The difference was probably due to the concentration of free fatty acids (acting as displacing agents) being higher in maternal serum. The transplacental binding gradient explains the clinical observation that total VPA levels at delivery are higher in the newborn than in the mother.
D003956:Dialysis; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D006801:Humans; D008431:Maternal-Fetal Exchange; D010121:Oxytocin / Q000494:pharmacology; D011247:Pregnancy; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism; D014635:Valproic Acid / Q000097:blood*
D005230:Fatty Acids, Nonesterified; D012709:Serum Albumin; D010121:Oxytocin; D014635:Valproic Acid