THE CONJUGATED, NON-PROTEIN, AMINO ACIDS OF PLASMA. V. A STUDY OF THE CLINICAL SIGNIFICANCE OF PEPTIDEMIA

Abstract

Factors affecting the validity of detns. of blood peptides were studied. The conjugated non-protein, amino acids (peptides plus other conjugates) of plasma were examined by the ninhydrin mano-metric method before and after hydrolysis. Tungstic acid filtrates of the plasma of normal fasting persons usually contained less than 1 mg. % of conjugated, non-protein, amino acid N, and in some cases the concn. was too small to be measured. Protein ingestion did not increase the concn. of conjugates; in fact, milk or casein produced decreases. Surgical procedures failed to produce increases of the "peptides" of plasma, nor were significant changes produced in the urinary excretion of free or conjugated amino acids. While the plasma of patients with a variety of diseases contained, as an avg., somewhat more amino acid conjugates than that of normal persons, most of the values were not outside the normal range. Free and conjugated amino acids of other body fluids were reported.