[A comparative study of the biological value of qualitatively different proteins and their susceptibility to attack by digestive proteinases]. / Sravnitel'noe izuchenie biologicheskoi tsennosti kachestvenno razlichnykh belkov i ikh atakuemosti pishchevaritel'nymi proteinazami.

It has been established that according to the principal criteria, namely the attackability by alimentary proteinases and biological value (potential and experimental), casein and fibrinogen are closely related proteins. Attackability of experimental casein (cleaned from glycomacropeptide) by alimentary proteinases rises after the action of denaturating agents. This fact brings together casein and globular proteins.

[Heterogeneity and physiological activity of bovine k-casein proteolysis products]. / K voprosu o geterogennosti i fiziologicheskoi aktivnosti produktov proteoliza korov'ego k-kazeina.

Gel chromatography in columns with Sephadex G-50 and biogel P-2 was used to separate a number of fractions formed in k-casein of cow's milk after short-term treatment with swine trypsin. These fractions, similar to beta-casomorphin, are capable of reducing the respiration and heart rates in rabbits after intravenous injection in a dose of 100 micrograms/kg, that suggests their capacity for interaction with opiate receptors. Some fractions injected subcutaneously induce in starving animals an electroencephalographic picture of satiation, similar to that observed after cholecystokinin injections. Correlation of amino acid composition and physiologic activity has evidenced that cholecystokinin and opioid effects are caused by different peptides.

[A peptide bioregulator from bovine kappa-casein]. / Peptidnyi bioreguliator iz korov'ego kappa-kazeina.

A number of peptides were isolated from pepsin hydrolyzate of cow k-casein by means of gel filtration on Sephadex G-50 and Biogel P-2, Dowex WX2 ion exchange chromatography in the pH step-wise gradient and dialysis using Sephadex G-10. The peptide material, after intravenous administration at a dose of 20 micrograms/kg of body mass, developed on electroencephalograms of various brain structures of starved rabbits the high amplitude, high frequent oscillations of electric potential corresponding to the effect of food satiation or to the action of cholecystokinin. Analysis of amino acid composition showed that the peptide fraction appears to be a fragment of para-k-casein moiety localized near one of Tyr residues containing in the protein molecule. Physiological effect of the peptide fraction was apparently related to regulation of satiation sense.

[Isolation, amino acid composition and type of action of gastric secretion inhibitors derived from k-casein]. / Vydelenie, aminokislotnyi sostav i kharakter deistviia ingibitorov zheludochnoi sekretsii iz k-kazeina.

Yield of an inhibitor of gastric secretion and its activity were increased after additional step of the k-casein purification as well as a result of increase in the enzyme/substrate ratio at the step of enzymatic hydrolysis and of substitution of the filtrate dialysis by extraction with ether. Amino acid analysis of the gel chromatographic fractions of inhibitor demonstrated the presence of para-k-casein fragments in its molecule. As shown by kinetics of inhibitory action the preparation included two inhibitors of gastric secretion. The inhibitor I exhibited its effect immediately after administration and increased the latent period of the gastric acidification. The effect of the inhibitor II was manifested with in 1.5-2 hrs after administration. The preparation isolated may be a useful drug in treatment of gastroduodenal impairments caused by hyperacidic states.

[Nitrogen metabolic indices of infants fed a new milk mixture]. / Pokazateli azotistogo obmena u detei pri vskarmlivanii novoi molochnoi smes'iu.

The efficacy of utilization of the protein compound from Ladushka, a new formula mixture, was studied in infants of the first 6 months of life, starting from the neonatal period. The protein component of the mixture consisted of casein and decalcified whey proteins (1:1). Calcium content comprised 400 mg/l, and its ratio with phosphorus approached the values recommended for formula feeding. The mass volumes of accessible lysine and cystine, despite additional enrichment of the mixture with these amino acids, were considerably reduced versus the expected values, that may be explained by insufficiently sparing technology of preparation.

[Effect of a diet containing a soy isolate on serum amino acid composition and on other interstitial metabolic indices in chronic hepatitis]. / Vliianie diety, soderzhashchei izoliat soi, na aminokislotynyi sostav syvorotki krovi i drugie pokazateli mezhutochnogo obmena u bol'nykh khronicheskim gepatitom.

The diet containing soybean protein in an amount of 22.4% of the total protein quantity exerts a beneficial effect on the clinical status and interstitial metabolism of patients with chronic hepatitis. No significant changes were found in the serum amino acid composition. A conclusion is made that soybean protein may be recommended for using in the dietetic management of patients suffering from chronic hepatitis.

[Xanthurenuria at different stages of liver lesion induced by protein and choline deficiency]. / Izuchenie ksanturenurii na razlichnykh stadiiakh povrezhdeniia pecheni, vyzbannogo defitsitom belka i kholina.

The parallelism between xanthurenuria and liver affections caused by protein and choline deficiency was studied. At the stages marking the development of lipohepatosis and fibrosis there occurred an intensive passage of xanthurenic acid. The intensity of xanthurenuria at the stage marking the appearance of hyperplastic nodes continued to gain strength. With progressive advance of pathological changes, which by the 9--12th months of the experiment reached the stage of a fully developed nodular cirrhosis xanthurenuria gradually stopped.

[Nitrogen-containing fractions of Soviet hydrolysates for parenteral feeding]. / Ob azotsoderzhashshikh fraktsiiakh otechestvennykh gidrolizatov dlia parenteral'nogo pitaniia.

The content of free amino acids, non-precipitable and precipitable trichloro-acetic acid peptides in Soviet-made hydrolysates for parenteral alimentation was determined. As shown, it is aminopeptide and aminosol that contain the greatest amounts of amino acids, fibrinosol and caseine hydrolysate carrying their least quantities, with aminocrovine and hydrolysine occupying an intermediate place in this respect. The quality of hydrolysates was assessed according to their biological value and to do so chemical numbers of essential amino acids were calculated and limiting factors determined. Fibrinosol and aminosol and to a somewhat lesser degree--casein hydrolysate were found to be best balanced as concerns their amino acids composition. Aminopeptide, hydrolysine and especially aminocrovine were manifestly inadequate by their biological value, since they contain limiting amino acids (isoleucine, cystine and methionine).

[Amino acid composition of proteins of the membranes of rat liver sucellular structures and the effect of protein deficiency on it]. / Aminokislotnyi sostav belkov membran subkletochnykh struktur pecheni krys i vliianie na nego belkovoi nedostatochnosti

The protein amino acids composition of nuclear, mitochondrial and lysosomic membranes and those of the endoplasmatic reticulum of the liver in rats receiving for 30 days rations with normal (18.5 per cent) and low (4 per cent) protein content was investigated. The amino acid spectra of proteins forming part of various cytomembranes, in spite of their considerable resemblance, are shown to have traits of a definite specificity. Protein deficit in the ration causes not only a fall of the total amino acid content in the membranous cellular structures, but it also attended by a deranged correlation among individual amino acids.

[Distribution of 14C-nicotinic acid in the organs of white rats with a prolonged protein and choline deficit]. / Raspredelenie 14C-nikotinovoi kisloty v organakh belykh krys pri dlitel'nom defitsite belka i kholina

In animals receiving for 12 months a ration deficiency of protein and choline distribution of 14C-nicotinic acid among their organs was determined. In the distribution 14C-nicotinic acid in the organs of the control and test groups of the animals no difference was in evidence.

[Free amino acids in human blood serum during endogenous alimentation]. / Svobodnye aminokisloty syvorotki krovi cheloveka v usloviiakh endogennogo pitaniia

It has been ascertained that the blood serum of individuals fasting for 20 days demonstrates a sharply pronounced derangement in the proportions of amino acids, i. e. a manifestation of an endogenous amino acids imbalance. The most steep is the rise in the content of isoleucine, leucine and valine. These data may be used in considering issues concrened with an upset metabolism of amino acids under conditions of endogenous alimentation.

[Influence of riboflavin on xanthuria leveloping as a result of protein and choline deficiency]. / O vliianii riboflavina na ksqnturenuriiu, voznikaiushchuiu pri defitsite belka i kholina

In growing male-rats intensively excreting xanthuric acid under the effect of rations deficient in protein and choline the passage of riboflavin with urine was determined. A series of tests with deficient choline in conjunction with a well-marked protein shortage revealed an intensive passage of riboflavin. On the other hand, a series of tests with deficient choline against the background of a moderate protein shortage failed to show any difference in the passage of riboflavin by test and control anomals. A single administration of 200 gamma of riboflavin to rats helped bring down elevated concentrations of xanthuric acid in the urine.

[Utilization of excess phenylalanine in the diet of rats to obtain an experimental model of phenylketonuria]. / K voprosu ob ispol'zovanii izbytka fenilalanina v ratsione krys dlia polucheniia éksperimental'noi modeli fenilketonurii

An excess of phenylalanine in the diet of rats was found to produce toxic action, especially strongly pronounced in animals receiving low-protein ration. A protein-rich diet is shown to produce a definite protective effect in acute poisoning with phenylalanine. In the blood and hepatic tissue of rats receiving for 15-30 days a diet containing 24 per cent of caseine and 7 per cent of phenylalanine there occurred a marked disproportion of free amino acids, i.e. a state of endogenous amino acids imbalance. The nature of biochemical disorders arising in the blood of these animals essentially differs from changes characteristic of the blood of the children suffering from phenylketonuria.