[About losses of macro- and trace elements during sport activity and expediency of their compensation by active dietary supplements].

The data about losses of macro- and trace elements during sports activity are incomplete and recommendations are contradictory. It seems that if energy intake is sufficient and nutritional status is in normal limits such mineral supplements is not warranted. Stable isotopes can play a unique role in studies of nutritional status, metabolism, absorption rates, and bioavailability of macro- and microelements.

[Express method to estimate alpha-amilase activity in specialized food products and dietary supplements].

More simple method to estimate of alpha-amilase activity in special foods and food supplements is proposed.

[Method of determining inuline in sugar-free foods and food supplements].

The article describes a method of determining inuline (inuline like fructans) in sugar-free foods and food supplements.

[Utilization of glucose, valine, glycerin and palmitic acid by energy and anabolic pathways of metabolism in rats]. / Utilizatsiia gliukozy, valina, glitserina i pal'mitinovoi kisloty po énergeticheskomu i anabolicheskomu puti metabolizma u krys.

Possibility of evaluation of nutrients use by energy and anabolic ways by measurement in blood of radioactivity of water formed from labelled by tritium precursors was studied. The experiment was made on rats, which consecutively with interval 1.5-2 weeks were given intravenous indicative amount of 3H2(2,3)-valine, 1-14C-glucose, 6-3H-glucose, 3H2(1,3)-glycerin and 3H2(9,10)-palmitic acid. Half-time of glucose in blood was 46 min, glycerin--16 min, valine and palmitic acid--24 min. Plastic and energy characteristics of these substances were studied. The proposed approach to the evaluation of plastic and energy functions of nutrients can be useful for development of specialized products for enteral and parenteral feeding.

[A new method of evaluating the utilization of nutrients (carbohydrates, amino acids and fatty acids) on the plastic and energy goals in the animal body]. / Novyi metod otsenki utilizatsii pishchevykh veshchestv (uglevodov, aminokislot i zhirnykh kislot) na plasticheskie i énergeticheskie tseli v organizme zhivotnykh.

With use of a new method, based on detection in blood serum of radioactivity of water, formed from tritium marked precursors--glucose, amino acids (valine, serine, histidine) and palmitine acid--their distribution on oxidizing and anabolic ways of metabolism was determined. The work was carried out on laboratory rats. In young pubertal rats the ratio of flows on these ways for glucose was found equal 2.83, i.e. it in a greater degree was used as energy substratum. On the contrary, for palmitine acid this ratio was equal 0.10--it was comprised in a plastic material of organism in a greater degree. For serine, histidine and valine it is equal 0.34, 0.71 and 0.46, accordingly. In growing rats the distribution of flows was shifted aside of anabolic way: the ratio of flows is equal 0.19; in old rats--aside of oxidizing: a ratio of flows is equal 0.71.

[Chronological parameters of carbohydrate utilization in the body]. / Vremennye parametry usvoeniia uglevodov v organizme.

The glycaemic index (GI) is reviewed as example of chronological parameters of carbohydrate utilisation. A food utilisation depends not only on nutrient composition and physical properties of food but also on body metabolism and physiological status including individual peculiarities, daily rhythm and other chronological characteristics of body connected with energy metabolism and biosynthesis of glycoproteins, phospholipids and nucleic acids. Such analytical approaches are very important for practice of human nutrition and animal feeding and also for critical analysis of "fashion" theories in nutrition.

[The ratio 3H/14C as an indicator of body adaptation to various dietary factors]. / Otnoshenie 3H/14C kak pokazatel' adaptatsii organizma k razlichnym pishchevym faktoram.

In experiments with Wistar rats was shown that ratio 3H/14C in tissues after ingestion of double labeled glucose can be used as indicator of metabolic effects of different dietary carbohydrates. Predominant utilization of glucose for lipid synthesis was determined in rats fed SKP (93.4% of oligosaccharides and dextrines) and absence this effect in rats fed dextrinomaltose (69% of maltose and 26.7% of oligosaccharides and dextrins).

[The effect of various types of dry starch syrup on the rate of glucose utilization in lipid, carbohydrate, and protein components of rat liver]. / Vliianie razlichnykh vidov sukhokrakhmal'noi patoki na tempy utilizatsii gliukozy v lipidnye, uglevodnye i belkovye komponenty pecheni krys.

Effect of a diet, containing dextran maltose and dry starch syrup, on some patterns of liver tissue metabolism were studied in young Wistar rats within 30 days. The animals of Control Group 1 were kept on a diet containing corn starch as a source of carbohydrates; in Group 2 the starch was replaced by the dry starch syrup enriched with disaccharides and especially with maltose; the dry starch syrup added into the Group 3 diet containing mainly oligosaccharides and polymers with high levels of glucose residues. The label mixtures of 6-3N- and 6-14C-glucose as well as of 6-3H- and I-14C-glucose were administered into the animals on the day of death. Analysis of the findings has shown that the products of starch hydrolysis may the specific parameters of glucose metabolism. Incorporation of the label into liver tissue lipids was similar to the control values in the group of animals kept on a diet enriched with maltose as compared with group 3. The glycolytic pathway of glucose utilization was more activated than the pentosephosphate pathway after substituting starch for dry starch syrup as shown by differences in the rates of carbon incorporation at positions 1 and 6 of a glucose molecule.

[Non-enzymatic glycosylation of dietary proteins by glucose and fructose]. / Nefermentativnoe glikozilirovanie pishchevykh belkov gliukozoi i fruktozoi.

Preliminary evaluation of glucose and fructose as glycosylation agents of some animal and vegetable food proteins has been presented. The study was conducted using the method of radioactive indicators. It has been shown that fructose binds proteins to a higher degree than glucose, and it can make for increasing glucose glycosylating activity in their combination in the product.

[Effect of carbohydrate structure on glucose utilization and biosynthesis of lipids, proteins and glucagon in rats]. / Znachenie struktury uglevodov dlia utilizatsii gliukozy v biosinteze lipidov, belkov i glikogena u krys.

It was established that utilization of labelled glucose depended on food carbohydrate structure. Saccharose increased 1.5-fold the labelling of lipids in the liver and lowered insignificantly glycogen labelling. Similar quantity of invert sugar sharply reduced glycogen labelling. When starch was substituted for corn syrup lipid labelling increased two-fold, while glycogen labelling decreased down to 26% of the control level. Lipid/glycogen labelling ratio in saccharose feeding was 2, in invert sugar--4, in corn syrup--17.

[Features of the effects of disaccharide structure of saccharose on kinetic parameters of hepatic lipid synthesis from glucose (mechanism of disaccharide effect)]. / Osobennosti vliianiia disakharidnoi struktury sakharozy na kineticheskie parametry sinteza lipidov pecheni iz gliukozy (k voprosu o mekhanizme disakharidnogo éffekta).

Effects of saccharose or invert sugar on kinetics of lipid synthesis in the rat liver were investigated using 1-14C-glucose as a precursor. The diet containing 30% of saccharose (of the total energy value) for 40 days was found to be sufficient to increase the radioactive carbon flux through total liver lipids more than twice, and through rapidly metabolized neutral lipids and phospholipids more than 4 and 3 times, consequently. On the contrary, when the invert sugar diet was used the radioactive carbon flux through total lipids in the liver was reduced up to 54% of the control level, the lowest radioactive carbon flux was observed through the rapidly metabolized fraction of phospholipids--6% of the control level, only. These changes were caused by the corresponding alterations in lipid synthesis constants.

[Effect of sucrose on lipid metabolism in rats: confirmation of the disaccharide effect]. / Osobennosti vliianiia sakharozy na metabolizm lipidov u krysy: podtverzhdenie disakharidnogo éffekta.

Disaccharide effect of sucrose on lipid metabolism was confirmed in male Wistar rats (initial weight 119-127 g). The rats were given rations containing either sucrose (30% of total caloric++ value), or invert sugar, or starch only (control). The duration of the dietary period was 40 days. To study lipid metabolism the rats were injected i. p. with 1-14C-glucose and 3H-palmitic acid. 14C-radioactivity increased in the total lipid of serum and epididymal adipose tissue, in liver phospholipids and mostly in liver neutral lipids with the saccharose-supplemented diet but not with invert sugar-supplemented diet. In contrast, 3H-radioactivity in liver phospholipids decreased in rats that were given saccharose, no changes were recorded in the animals fed with invert sugar or starch.

[Nonenzymatic glycosylation of serum albumin and thymic DNA by food monosugars and their natural metabolites that form in the body]. / Nefermentativnoe glikozilirovanie syvorotochnogo al'bumina i DNK timusa pishchevymi monosakharami i ikh estestvennymi metabolitami, obrazuiushchimisia v organizme.

The nonenzymatic glycosylation of human plasma albumin by glucose, fructose, xylose, glucose-6-P, fructose-6-P, 6-PP was studied in vitro. The most manifest differences in the albumin spectrum (250-390 nm) were observed when fructose-6-P and xylose were used. The use of 3H-glucose and 14C-fructose has shown that there are 2 sites for glucose addition, 4 sites for fructose addition and 1 site to which both glucose and fructose can be bound, but glucose is preferable. Calf thymus DNA has 10 sites to which carbohydrate can be bound: 4 for glucose and 6 for fructose, only.

[New data on the metabolism and physiologic mechanisms of aspartame action]. / Novye dannye o metabolizme i fiziologicheskom mekhanizme deistviia aspartama.

A comprehensive investigation of the physiological action of aspartame was conducted in 11 volunteers (healthy subjects, aged 18-37 years, with normal bw), and in experiments on 90 male Wistar rats, that were given aspartame in doses of 40 and 4000 mg/kg during 90 days, and in 3 dogs with gastric fistulas according to Basov. The study of microsomal and lysosomal activities in the liver, the turnover rate of liver proteins and blood plasma in rats revealed changes in the activity of liver cathepsins and in blood plasma albumin life time. The reaction of food thermogenesis after aspartame intake was recorded in experiments on dogs, that received sham feeding, and in the volunteers. As a whole, in the experiments including aspartame intake in a permissible daily dose for humans (40 mg/kg) no unfavourable action of the agent on the metabolic parameters studied was recorded.

[The significance of the structure of dietary oligosaccharides in their metabolism into liver lipids]. / Znachenie struktury pishchevykh oligosakharidov dlia ikh utilizatsii v lipidy pecheni.

In experiments on 24 Wistar male rats the time course of incorporation of radioactive carbon and hydrogen of glucose and fructose into liver lipids was studied, as well as the influence on this process of the animals feeding with rations containing sucrose and inverted sugar (17% calory value). A mathematical model has been suggested for the evaluation of the effect of sugar and a glucose-fructose mixture on monosugar utilization into liver lipids. It was found that sucrose led to an increase in the rate of the label incorporation into liver lipids from glucose and fructose, and to a growth in the constant of the label release from lipids, i.e. induced acceleration of the liver lipid turnover. These effects were absent in rats given inverted sugar.

[Effect of moderate amounts of food saccharose on glucose and fructose metabolism in the liver of rats]. / Vliianie umerennykh kolichestv pishchevoi sakharozy na metabolizm gliukozy i fruktozy v pecheni krys.

Thirty-six male Wistar rats received rations containing 0, 5 or 15% sucrose during 40 days. Significant changes were recorded in the utilization of 6-3H-glucose for the synthesis of lipids and glycogen of the liver. The effect of sucrose feeding on hepatic lipid metabolism depended on the sucrose level: 6-3H-glucose incorporation into liver lipids increased after feeding with the ration containing 5% sucrose, while it was suppressed by 15% sucrose. 6-3H-glucose incorporation into glycogen of the liver was suppressed by both sucrose levels in the ration. U-14C-fructose incorporation into liver glycogen and lipids was not affected by sucrose feeding.

[Use of fructose as an energy substrate in the body of rats given food containing various amounts of carbohydrate]. / Ispol'zovanie fruktozy v kachestve énergeticheskogo substrata v organizme krysy pri razlichnom uglevodnom sostave pishchi.

Production of radioactive CO2 from 14C-fructose administered intraperitoneally was studied in 18 male Wistar rats given food containing saccharose with calorific value of 0-56%. Intensive CO2 labeling was completed 3-4 h after 14C-fructose administration. More radioactive CO2 was formed in rats which received food without fructose, during first 30-60 min after 14C-fructose administration. About 20-30% of radioactivity introduced with fructose was excreted from the body with CO2 expired during 6 h, that correlated with the data on CO2 production from glucose. Thus, despite a number of principle differences in fructose and glucose metabolism, similar portions of their pool are used for direct provision of the body with energy.

[Effect of food carbohydrate quality on monosaccharide utilization for the biosynthesis of glycogen, fat and proteins in the rat liver]. / Vliianie kachestva uglevodov pishchi na utilizatsiiu monosakharov dlia sinteza glikogena, zhira i belkov v pecheni krys.

The inclusion of 3H-6-glucose and 14C-fructose metabolites into the rat liver glycogen, lipids and protein was studied in male rats receiving the rations containing 56% of carbohydrates, 18% protein, 26% fat, necessary amount of mineral substances and vitamins, during 25 days. Animals given the ration with starch, as a carbohydrate, were used as controls. In the ration of animals in groups 2, 3 and 4 some portion of starch (30% calorific value) was substituted for glucose, sucrose of the mixture of glucose and fructose (1:1). It was found that in the liver of animals given pure starch, radioactivity from 3H-6-glucose was included mainly into proteins, when starch was partly substituted for monosaccharide--mainly into lipids. These regularities were recorded in the distribution of radioactivity from 14C-fructose, all the parameters being shifted in the direction of increased inclusion of radioactivity into lipids. Partial substitution of starch for sucrose specifically changed the radioactivity distribution between proteins and lipids, thus revealing a distinct "disaccharide" effect.

[Effect of a carbohydrate-free diet on changes in lipid and proteins levels in rat tissues]. / Vliianie bezuglevodnogo ratsiona na obnovlenie lipidov i belkov v tkaniiakh krys.

The influence of carbohydrate-free and high-fatty (82% calorific value) ration on the content and turnover of proteins and lipids in the liver and perirenal fatty tissue was studied in experiments in vivo, in male Wistar rats (n = 23) with initial body weight (bw) 200 +/- 10 g. One month after the feeding with the ration studied bw of rats given carbohydrate-free diets did not differ from that of the control animals. The protein content was decreased and its turnover slowed down in hepatocytes of rats given carbohydrate-free ration. No significant changes were detected in the lipid content and turnover in hepatocytes. No changes were recorded in the protein content and turnover in the rat fatty tissue; however, significant changes were observed in the lipid turnover. They were manifest in an increased use of ramified aminoacid metabolites in lipid synthesis, and in speeding up the lipid turnover.