Amino acid content of preimplantation rabbit embryos and fluids of the reproductive tract.

As a companion to amino acid transport and protein synthetic studies, it was of interest to quantify the amino acid pools in embryos and reproductive tract fluids during preimplantation development. Primary amines in the acid-soluble extracts of embryo and fluid samples were separated by high-performance liquid chromatography, reacted with o-phthalaldehyde, and quantified by fluorescence emission. The amino acid compositions of embryos were like those of corresponding reproductive tract fluids. Taurine was high in eggs and fluids but declined with development, while glycine levels rose. Glycine was highest in concentration in all samples (except the egg), followed by glutamate and alanine, while most other amino acids were consistently of low abundance.