The effect of alpha-aminoisobuturic acid and 2,4-diaminobuturic acid on mouse blastocyst outgrowth in vitro.
Blastocysts recovered from mice in a state of delay of implantation were incubated for 10 h with either alpha-aminoisobuturic acid (AIB) or 2,4-diaminobuturic acid (DAB), two non-metabolizable amino acids. The incubation medium was composed so as to maintain growth arrest of the inactive, delayed blastocysts in vitro. The blastocysts were then transferred to a complete outgrowth medium without the two non-metabolizable amino acids to test the capacity for trophoblast outgrowth. AIB, which displays saturation kinetics, was harmless to the blastocysts even at a high concentration, while DAB at a low concentration irreversibly damaged the trophoblast cells and prevented outgrowth, probably due to nonsaturation kinetics resulting in a high intracellular accumulation. The harmful effect of DAB could be abolished by concomitant incubation with L-alanine and L-methionine, which compete with DAB for the same transport system, while the D-forms of the same amino acids had little or no effect. The results suggest the presence of transport System A in mouse blastocysts growth arrested in vitro, indicating an operative carrier mechanism already during delay of implantation.
D000409:Alanine / Q000494:pharmacology; D000599:Amino Acids, Diamino / Q000494:pharmacology; D000613:Aminobutyrates / Q000494:pharmacology*; D000621:Aminoisobutyric Acids / Q000494:pharmacology*; D000818:Animals; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D002478:Cells, Cultured; D003470:Culture Media; D005260:Female; D008525:Medroxyprogesterone / Q000494:pharmacology; D008715:Methionine / Q000494:pharmacology; D051379:Mice; D011247:Pregnancy; D014327:Trophoblasts / Q000166:cytology
D000599:Amino Acids, Diamino; D000613:Aminobutyrates; D000621:Aminoisobutyric Acids; D003470:Culture Media; D008715:Methionine; D008525:Medroxyprogesterone; D000409:Alanine