Stimulatory and inhibitory effects of amino acids on the development of hamster eight-cell embryos in vitro.

Amino acids were added to a simple medium (TALP) in an effort to enhance the development of hamster eight-cell embryos in vitro. The addition of 1.0 mM glutamine to TALP medium markedly increased the percentage of embryos reaching the blastocyst stage. The addition of groups of 4 or 20 amino acids to TALP + glutamine medium produced differential effects, some groups inhibiting development while others stimulated it. The beneficial effect of glutamine was on the eight-cell to morula transition as well as on blastocyst formation, while the effects of the other 20 amino acids studied were only on blastocyst development. This study represents further progress made in identifying the culture requirements for growth of hamster preimplantation embryos in vitro.