Transport of amino acids in the placenta

Carrier-mediated transport of monocarboxylic acids in BeWo cell monolayers as a model of the human trophoblast

“…Open Access version: http://kuscholarworks.ku.edu/dspace/. 4 polycarbonate filters (13 mm diameter, 0.4 µm pore size) were purchased from Fisher Scientific. All other chemicals were of the purest available analytical grade and purchased from Fisher or Sigma (St. Louis, MO).…”

“…In general, the absorption of drugs across the single layer of trophoblasts can be explained in terms of the pH-partition hypothesis which is well illustrated by passive diffusion mechanisms. 1,2 However, with the use of brush-bordermembrane vesicle techniques or cultured cells 3 , it has become increasingly clear that there are a number of carrier-mediated transport mechanisms present at the placental barrier including systems for amino acids 3,4 , transferrin 5 , and dopamine 6 . These carriers take on pharmaceutical relevance due to the fact that nutrients, hormones, as well as, drugs and drugs of abuse can be transported across the placental barrier by these mechanisms.…”

Taurine Transport in the in Vitro Perfused Human Placenta

“…Most amino acids studied cross the placenta by an active transport mechanism (22,(29)(30)(31)(32). A dual transfer phenomenon, one saturable and the other nonsaturable, has been demonstrated in human placental villous fragments, vesicles and slices (33)(34)(35).…”

Selective Impairment of Taurine Transport by Cyclosporin A in a Human Placental Cell Line

“…There are multiple transport systems in the human placenta that mediate the transfer of amino acids from mother to fetus (7). At least three systems serve neutral a-amino acids (systems A, ASC, and L) (8,9) and one each for P-amino acids (system P) (lo), acidic amino acids (system XAG-) (1 I), and basic amino acids (system y+) (12).…”