title: Umbilical venous-arterial differences of plasma amino acids in humans at midpregnancy.
abstract: The plasma levels of 20 free amino acids in the umbilical vein (UV) and the umbilical artery (UA) of seven newborns (20-24 weeks gestation) were measured at delivery. Seven (lys, val, leu, thr, his, ile, phe, and met) of the essential amino acids and six [ala, glu (NH2), arg, pro, 1/2 cys, and asp (NH2)] of the nonessential amino acids were shown to be significantly higher in UV than in UA. Among these amino acids, alanine showed the largest value for umbilical venous-arterial difference (UV-UA). Total plasma amino acid concentration was shown to be higher in the UV than in the UA. The general pattern of UV-UA for plasma amino acids in newborns studied here was proven to resemble closely that of premature births reported earlier.
mesh_terms: D000596:Amino Acids / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism*; D005333:Fetus / Q000378:metabolism; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D014469:Umbilical Arteries; D014471:Umbilical Veins
chemical_list: D000596:Amino Acids