title: The relationship between placental protein synthesis and transfer of amino acids.
abstract: The relationship between placental protein synthesis and transfer of amino acids from mother to foetus was studied in the guinea pig, by using [U-14C]-lysine, -leucine, -glycine, -aspartate and -alpha-aminoisobutyrate. The uptake of label by protein was 12-16% of total label transferred. Cycloheximide inhibited incorporation of all naturally occurring amino acids into protein by 81-96% and transfer by 62-75%; the concentration of label in the free pool was increased for each. These findings were confirmed when specific-radioactivity measurements were made with L-[U-14C]lysine. The transfer of the non-protein amino acid alpha-aminoisobutyrate was not significantly decreased by cycloheximide. A model, linking protein synthesis to the generation of a transfer pool of amino acids, is proposed whereby inhibition of protein synthesis decreases the amount of amino acid available for transfer.
mesh_terms: D000596:Amino Acids / Q000097:blood / Q000378:metabolism*; D000818:Animals; D003513:Cycloheximide / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D006706:Homeostasis; D008431:Maternal-Fetal Exchange / Q000187:drug effects; D008954:Models, Biological; D010920:Placenta / Q000187:drug effects / Q000378:metabolism*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000096:biosynthesis*
chemical_list: D000596:Amino Acids; D011257:Pregnancy Proteins; D003513:Cycloheximide