Research-ArticleOptimum Amino Acid Complement for Protein Synthesis by Rat Mammary Cells in Tissue Culture1

The amino acid requirement of rat mammary cells for milk protein synthesis was investigated in dispersed cell culture. A three-dimensional central composite design utilizing three variables (X1 = lysine; X2 = methionine, valine, and arginine; X3 = isoleucine, tryptophan, threonine, phenylalanine, and histidine) at five concentrations each, was duplicated twice with mammary cells from lactating Sprague-Dawley rats. The optimum combination of amino acids for maximum milk protein synthesis from multiple regression models was X1 15.0-, X2 4.5-, and X3 1.5-fold their quantities in Eagle's minimal essential medium with leucine, tyrosine, cystine, and glutamine at the base 1-fold in the medium.