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Biomedical subjects

G A Sytov

Publications and source records attributed to G A Sytov.

8 recordsLinked to original sources

[To the question of the possibility of oral insulin administration].

The influence of oral insulin upon carbohydrate exchange in healthy volunteers was evaluated. One of the two forms of insulin used in the study was insulin, immobilized in a volume of polyacrylamide gel, modified by ovomucoid (proteolytic enzyme inhibitor), isolated from duck eggs; the other form was enteric-coated tablets bases on hydrogel substance. The oral administration of the hydrogel substance or the tablets resulted in the fall of blood glucose concentration by 34.9 +/- 4.4% and 28.6 +/- 6.9%, respectively. The maximal effect of the hydrogel substance and the tablets was observed at the 90th and the 180th minutes.

Administration, Oral↗

Mucoadhesive polymers with immobilized proteinase inhibitors for oral administration of protein drugs.

A new approach to overcome the degradation of protein drugs by proteolytic enzymes and their targeting to the blood through the digestive apparatus was developed. The approach is based on the immobilization of drugs into the polymeric hydrogel containing glycoprotein--ovomucoid from duck egg whites. This glycoprotein inhibits the activity of proteolytic enzymes and acts as a biospecific ligand to lectins on the walls of the gastrointestinal tract.

Administration, Oral↗

[Synthesis and study of immobilized insulin].

Conjugates of insulin with duck egg-white ovomucoid and soybean trypsin inhibitor were synthesized. The conjugates are highly stable to alpha-chymotrypsin treatment. Oral administration of insulin-ovomucoid conjugates in rabbits significantly lowered blood glucose level unlike administration of insulin-soybean trypsin conjugate.

Animals↗

[Inhibitors of proteolytic enzymes in the treatment of diabetes mellitus].

A new approach to overcome the degradation of insulin by proteolytic enzymes and its targeting to the blood through the digestive apparatus was developed. The approach is based on the immobilization of insulin into the polymeric hydrogel which is modified by ovomucoid--glycoprotein, inhibitor of proteolytic enzymes. Oral administration of this system to rabbits and rats, (in contrast to the hydrogels modified by proteolytic enzymes inhibitors without polysaccharide part), statistically significantly lowered blood glucose level.

Animals↗

[Stability of immobilized insulin preparation at various pH].

The stability of polyacrylamide hydrogel, modified by ovomucoid with immobilized insulin was studied at different pH of external medium. At 3.8 < pH < 5.5 insulin binds to the gel, due to electrostatic interaction between ovomucoid and insulin molecules.

Acrylic Resins↗

[Oxidase activity of horseradish peroxidase in oxidation of the bilirubin-albumin complex].

The catalytic activity of horseradish peroxidase was investigated upon oxidation of the bilirubin-albumin complex (10(-5)-10(-4) M; BR: SA = 1: 1.5 mol/mol) by dissolved oxygen to biliverdin and other components. The process can be described by the Michaelis-Menten equation with Km = 14.4 microM and Vmax = 0.12 microM/min, if HRP = 3.1 x 10(-8) M. Oxidation is supposed to proceed in the triple complex--peroxidase: albumin: bilirubin.

Animals↗

[Problems in creating insulin preparations with increased stability against proteolysis].

Chemical methods that accelerate the transport of insulin and other polypeptides across biological membranes and increase their resistance to enzymatic hydrolysis are reviewed. These methods include chemical modification of insulin macromolecules, the use of compounds that increase the permeability of biological membranes or inhibit enzymatic proteolysis, the hormone immobilization in a polymer coat protecting it against the aggressive environment, the incorporation of insulin into liposomes, etc. The advantages and drawbacks of these methods are analyzed, and promising lines of research in this field of applied biochemistry are described.

Amino Acid Sequence↗