High Levels Of Alanine Research Articles

An antigenic antimorphogenetic bone hydrophobic glycopeptide (AHG).

A hydrophobic glycopeptide, isolated from fresh marrow-free cortical bone of the rat, extinguished the bone morphogenetic response of insoluble bone matrix gelatin which otherwise invariably produces new bone from migrating mesenchymal cells after implantation in muscle of the rat. Incubation of the 10 to 100 mug of the glycopeptide per milligram of bone gelatin in phosphate or Tris-HCl buffer, pH = 7.4, for 24 hours recombines the hydrophobic polypeptide and gelatin. Incubated with doses of 50 to 100 mug, implants of gelatin in Sprague-Dawley recipients are rapidly resorbed by a lymphocyte-plasma cell-macrophage infiltrate without developing any new bone. With 10 to 20 mug, infiltrate appears and bone develops inversely in proportion to the dose. Bone develops at all dose levels only when bone matrix gelatin and glycopeptide were prepared from an inbred strain of Lewis rats and recipients were of the same strain, and thereby suggests that only allogeneic AHG, produces an antigenic antimorphogenetic resonse. The glycopeptide was isolated from bone together with lipids and other hydrophobic proteins or polypeptides by chloroform-methanol (1:1) extraction and further purified by chromatography on ion-exchange columns and molecular sieves. The molecular weight established by Sephadex G-100 filtration and by calibrated dialysis is about 5000 daltons. Analysis of the biologically active fraction shows 75% of proteinaceous material and close to 25% carbohydrate with trace amounts of hexosamines and sialic acid. Amino acid analysis shows high levels of alanine, valine and leucine in comparison to other chloroform-methanol extractable but immunogenically relatively-inactive fractions.

Amino acids in Hordeum distichon and Panicum miliaceum grown in sand culture

In comparison with barley, Proso millet was characterized by high levels of alanine and glutamic acid in the leaf free amino acid fraction. In both species, analyses of root amino acids and xylem exudates suggest the existence of specific mechanisms for the transfer of certain amino acids into the xylem vessels.

Amino acid metabolism in lactic acidosis

Individual plasma amino acid levels have been determined in six patients with severe lactic acidosis. A consistently distorted pattern was observed whether the disorder was due to shock or was of the idiopathic type. A sixfold elevation in mean alanine concentration was observed, and a significant correlation of alanine with pyruvate concentrations was demonstrated. Since alanine is normally released from muscle and stoichiometrically extracted by liver, normal formation of alanine from pyruvate is suggested by the findings. However, uptake and metabolism of alanine by isolated, perfused rat liver was significantly inhibited by perfusate concentrations of lactate and pyruvate equivalent to those observed in the patients. Thus the high levels of alanine in lactic acidosis are viewed as consistent with normal or increased peripheral release combined with impaired hepatic disposal. The levels of fifteen of the nineteen amino acids measured were elevated. Of the remaining four, three were intermediates of the urea cycle.