Incorporation of Radioactive Amino Acids into Oral Tissue Proteins

¹ University of Illinois Medical Center, Chicago, Illinois

The characteristics of an amino acid incorporation system in the lingual palatal raphe of the guinea pig were studied. Slices of lingual palatal raphe incorporated leucine-C¹⁴ into its protein faster than an equivalent liver slice system. The proteins that become radioactive are those of the guinea pig tissue and are not proteins of bacteria that may contaminate the preparations.

Anaerobiosis and 24-hour fasting inhibited the incorporation of the amino acids, as did the absence of endogenous or exogenous glucose. Inhibitors of oxidative phosphorylation sharply decreased the incorporation of the amino acids into protein.

Most of the labeled protein appears to be in the epithelial layers of the tissue, although some connective tissue protein does become labeled.

These results strongly suggest that the pathways of protein biosynthesis in oral tissues are the same as that previously reported for liver, muscle, and other tissues.