PEPTIDE-BOUND METHIONINE AS METHIONINE SOURCES FOR PROTEIN ACCRETION AND CELL-PROLIFERATION IN PRIMARY CULTURES OF OVINE SKELETAL-MUSCLE

Ruminants have high concentrations of peptide-bound amino acids in the circulation. Earlier studies in our laboratory showed that a myogenic cell line (C2Cl2) developed from mouse skeletal muscle and a mammary epithelial cell line (MAC-T) developed from bovine mammary epithelial tissues are able to utilize peptides as amino acid sources, In this st udy, primary cultures of ovine myogenic satellite cells were evaluated for their ability to use peptide-bound methionine as a source of meth ionine for protein accretion and cell proliferation, The basal medium contained methionine-free Dulbecco's modified Eagle's medium supplemen ted with 6% desalted fetal bovine serum, Treatment media included the basal medium supplemented with no methionine, methionine or one of 22 methionine-containing peptides, No protein or DNA accretion was observ ed in the presence of basal medium alone, Growth responses to all of t he peptides were obtained, with protein and DNA accretion ranging from 49 to 107% and from 45 to 144% of the corresponding methionine respon se, respectively, These results indicate that the ovine myogenic satel lite cells possess the ability to utilize methionine-containing peptid es as methionine sources for protein accretion and cell proliferation.