[Digestive enzyme activities in rats kept on standard or surplus breast-feeding and on low-protein diet directly after weaning].

Activities of digestive enzymes (maltase, alkaline phosphatase, amino peptidase M, and glycyl-L-leucine dipeptidase) in small and large intestine, liver, and kidney were studied in rats of different ages kept in normal (8) and low (3) amounts of pups per litter. The low-protein diet for 10 days at once after weaning was found to change the mass of the organs and their digestive enzyme activities in all studied rat groups. The revealed changes were more prominent in rats kept under conditions of breast-overfeeding. In adult animals of this group, distribution of the alkaline phosphatase activity along the small intestine differed from that in control rats. The obtained results seem to confirm the fact that any disturbance of the nutrition quality in early ontogenesis leads to disturbance of the "metabolic programming of enzyme systems" of digestive and non-digestive organs.

[Effect of weaning terms and protein deficit in the rat pup nutrition on activities of digestive enzymes].

Restriction of protein in nutrition of rat pups weaned at different terms has been found to produce changes in activities of digestive enzymes (maltase, alkaline phosphatase, aminopeptidase M, and glycyl-L-leucine dipeptidase) in the small and large intestine both at once after cessation of nutrition with low-protein diet for 10 days and 4 months later. In adult animals after the earlier or later weaning there are observed not only a decrease or increase of the enzyme activities, but also a different type of distribution of the alkaline phosphatase activity along the small intestine, which is more pronounced in the lately weaned rats. Thus, disturbance of metabolic programming of enzyme systems of the small and large intestine due to a change of quality of nutrition in early ontogenesis depends on terms of weaning of animals.

[Effect of peptide Livagen on activity of digestive enzymes in gastrointestinal tract and non-digestive organs in rats of different ages].

It is stated that Livagen (Lys-Glu-Asp-Ala) is a weakly hydrolyzed peptide. Peptide hydrolases of small intestine do not hydrolyze Livagen even to a small extent. Under in vitro conditions Livagen reduces glycil-L-leucinedipeptidase activity in small intestine by 50%. After two weeks of Livagen administration per os in rats the digestive enzymes activity in young animals reduces, while in old animals it increases. It should be mentioned that the activity of enzymes in old rats after Livagen administration in the majority of cases approaches to the level of the activity in young animals of control group.

[Effect of age and radiation exposure on the frequency of translocations and dicentrics detected by FISH method in human lymphocytes]. / Vliianie vozrasta i oblucheniia na chastotu translokatsii i ditsentrikov, opredeliaemykh metodom FISH, v limfotsitakh cheloveka.

The frequencies of translocations and dicentrics detected by "chromosome painting" in lymphocytes were estimated in 115 healthy donors and in 273 people exposed to uncontrolled irradiation at low doses 1-4 years ago. Age responses of both types of exchanges at the age range from 3 to 85 years fit to quadratic model. The frequency of translocations grew faster with age than the frequency of dicentrics. The yields of stable exchanges in exposed people was significantly higher than those in control donors of corresponding ages.

[Comparison of cytogenic response of human lymphocytes to in vivo and in vitro exposure to low doses of gamma-rays. Unstable chromosomal exchanges detected by FPG techniques]. / Sravnenie tsitogeneticheskoi reaktsii limfotsitov cheloveka na obluchenie v malykh dozakh gamma-izlucheniia in vivo i in vitro. Nestabil'nye khromosomnye obmeny, opredeliaemye FPG-metodom.

On peripheral lymphocytes of eight cancer patients undergone whole-body therapeutic irradiation (at daily dose of 10 cGy up to total dose of 50 cGy of 60Co gamma-rays) the dose-response of unstable chromosome exchanges (dicentrics and centric rings) was studied. This dose response fitted well linear function. The lower slope of dose-response curve was found for in vivo irradiated lymphocytes as compared to the dose response curve obtained for in vitro irradiated lymphocytes of the same patients. This finding seems to provide evidence that in case of protracted irradiation of individuals an absorbed dose could be underestimated if for biological dosimetry an in vitro dose response curve for unstable chromosome aberrations is used as referent one.

[Comparison of cytogenetic response of human lymphocytes to in vivo and in vitro exposure to low-dose gamma rays. Translocations and dicentrics detected by the FISH technique]. / Sravnenie tsitogeneticheskoi reaktsii limfotsitov cheloveka na obluchenie v malykh dozakh gamma-izlucheniia in vivo i in vitro. Translokatsii i ditsentriki, opredeliaemye FISH-metodom.

On peripheral lymphocytes of 5 cancer patients undergone wholebody therapeutic irradiation (at daily dose of 10 cGy up to total dose 50 cGy of 60Co gamma-rays) the dose response of unstable and stable chromosomal exchanges detected by FISH was compared with the dose response of the some aberrations in lymphocytes irradiated in vitro. The dose response fitted well to linear function. For dicentrics the lower slope of dose-response curve was found for in vivo irradiated lymphocytes as compared to the dose-response curve obtained for in vitro irradiated lymphocytes of the same patients. No difference between in vivo and in vitro irradiation of lymphocytes was found for translocations. The frequency of translocations increased faster with the dose than the frequency of dicentrics only in lymphocytes irradiated in vivo.

[The dependence of the frequency of stable and unstable chromosome aberrations on the dose of the irradiation of human lymphocytes in vitro]. / Zavisimost' chastoty stabil'nykh i nestabil'nykh aberratsii khromosom ot dozy oblucheniia limfotsitov cheloveka in vitro.

Two methods (FISH and Giemsa) were used to estimate the frequency of stable and unstable chromosome aberrations in human lymphocytes exposed to gamma-irradiation in vitro in the dose range of 0.1 to 1.5 Gy. The DNA-probes specific to the chromosomes 1, 4, and 12 were used in combination with a pancentromeric probe. It was revealed that the dose-effect dependences for translocations (FISH) and dicentrics (FISH and Giemsa) were similar and could be adequately described by a linear-quadratic function.

[The digestive barrier functions of the enzymatic systems of the normal small intestine and in pathology]. / Pishchevaritel'no-bar'ernye funktsii fermentnykh sistem tonkoi kishki v norme i pri patologii.

The fact that the enzymes splitting food nutrients, those of protein nature in particular, not only in the epithelial cells of the small bowel, but in the lower structures of the intestinal wall, i.e. in the stromal and muscle serous layers, is shown for the first time. They are integral parts of the intestinal enzymatic barrier that protects the internal medium of the body from penetration of proteins and peptides. The activities of the enzymes which are present in the epithelial, stromal, and muscle serous layers have been demonstrated to be substantially changed in disorders (immobilization in the presence of starvation, surgical interventions into the small bowel). It is suggested that examining the functions of the postepithelial enzymatic barrier along with those of the epithelial and immunological ones will provide a deeper insight into some certain disorders of the alimentary tract.

[The current concepts on the absorption of monosaccharides, amino acids and peptides in the mammalian small intestine]. / Sovremennye predstavleniia o vsasyvanii monosakharidov, aminokislot i peptidov v tonkoi kishke mlekopitaiushchikh.

The review is mainly devoted to the development of ideas about absorption, or transport, of basic nutrients in the small intestine in humans and higher animal. The absorption processes have been characterized on the example of such substances, vital for organism, as carbohydrates and proteins. The review considers a molecular structure of transporters--protein molecules, which take part in a transfer of the products of lumenal and membrane digestion of carbohydrates (glucose, galactose, fructose) and proteins (amino acids, oligopeptides) across the enterocyte membranes. An information is presented about genetic disturbances of transport of certain amino acids during such diseases as Hartnup disease, cystinuria, and iminoglycineuria.

[Academician Aleksandr Mikhailovich Ugolev. The development of his scientific ideas]. / Akademik Aleksandr Mikhailovich Ugolev. Razvitie nauchnykh idei.

The science suffered a severe loss with the sudden death in November 2, 1991, of and outstanding physiologist Academician Alexander Mikhailovich Ugolev at the age of 66. All life of this man was devoted to the development of the national science. It was the aim and meaning of his life, he has contributed to scientific progress in every possible way. The major scientific interests of A. M. Ugolev were focused on the basic and applied areas of food assimilation, including the physiology of nutrition and digestion. The works of the scientist in this field of knowledge were world-wide recognized. During his scientific activity Dr. Ugolev conducted a number of brilliant studies which remained unforgettable trace in physiology and for ever will be a part of golden fund of science. This was promoted by a unique combination of his illustrious abilities of physiologist and general biologist as well as evolutionist with the gift of experimenter and excellent surgeon. His experimental skill can serve and example of an elegant combination of bold intentions and their masterly realizations. But the most remarkable and world-wide recognized discovery of the scientist was that of membrane digestion--previously unknown mechanism of food assimilation. Just this basic discovery is emphasized in the review devoted to the memory of unforgettable master. The fragmentariness of material depends on a desire to present concisely the major characteristics of membrane digestion.

[Adaptation of intestinal peptide hydrolases to different diets]. / Adaptatsiia kishechnykh peptidgidrolaz k razlichnym dietam.

Rats received for 7 days specialized high protein, fat and carbohydrate diets, in the conditions of maintenance of coprophagy and in the absence of hypodynamia, developed adaptive changes in the intestinal di- and tripeptide hydrolases. The enzyme adaptation was more pronounced in the proximal small intestine of the rats kept predominantly on the protein diet. The role of coprophagy as a possible mechanism of chemical homeostasis, is discussed.

[The enzymatic barrier of the small intestine]. / Enzimaticheskii bar'er tonkoi kishki.

The small intestine's barrier functions are reviewed. The data on mechanical (passive) and active protective systems of the organism against various antigens, toxic substances and proteins, is presented. An important role of these protective systems as an enzyme apparatus of epithelial and postepithelial layers of the small intestine's mucose, is shown.

[Radial and proximo-distal distribution of hydrolytic enzymes in the small intestine at rest and during digestion]. / Radial'noe i proksimo-distal'noe raspredelenie gidroliticheskikh fermentov v tonkoi kishke v pokoe i pri pishchevarenii.

Alpha-amylase was present in considerable amount in the chyme in rats both at rest and during digestion, in the latter case its level being increased. Activity of intrinsic intestinal enzymes dominated in the homogenate of the mucosa. Transition from fasting to feeding and digestion increased the level of alkaline phosphatase and dipeptidase activities in the homogenate of the mucosa. The data obtained suggest the final stages of biopolymers' hydrolysis to be localized in various enterocyte structures. The surface mucus, owing to absorbed pancreatic enzymes, binding proteins and other types of physiologically active molecules, is assumed to play the role of a specific molecular filter and take part in the initial stages of digestion.

[The detailed characteristics of the enzyme spectrum of the small intestine in rats in the early postnatal period]. / Detal'naia kharakteristika fermentnogo spektra tonkoi kishki krys v rannem postnatal'nom periode.

The activity of the small intestine's peptide hydrolases is higher in 1-day old rats than in adult rats, whereas levels of activity of alkaline phosphatase and diglycyl glycine peptidase do not differ significantly in these two groups of the rats. Our own data on carbohydrases corroborate other authors' evidence and reveals that activities of lactase, sucrase and maltase are either absent or very low in the first days of life and sharply increase by the third week of postnatal development. Adaptive changes of regulatory properties of lactase and alkaline phosphatase are revealed.

[Interrelationships between the enzymatic functions of the pancreas and small intestine during adaptive processes]. / Vzaimootnosheniia fermentativnykh funktsii podzheludochnoi zhelezy i tonkoi kishki pri adaptivnykh protsessakh.

In rats fed for 4, 15, and 30 days with increased amount of proteins, lipids, and carbohydrates, considerable shifts occurred in activity of enzymes of the pancreas (amylase, protease, and lipase) and small intestine (gamma--amylase, maltase group, invertase, peptidhydrolase, monoglyceriflipase). Mathematical analysis suggested a close connection between the adaptive shifts in the enzyme systems maintaining the lumen and the membrane types of digestion. The protein diet augments the proteolytic enzyme chain the lipid diet--the lipolytic chain, and the carbohydrate diet--the carbohydrate chain. The shifts should be regarded as an integrative adaptive response of the enzyme spectrum of the pancreas and small intestine to alterations in the food composition.

[The digestive enzymes in the gastrointestinal tract, kidney, liver and spleen in different functional states]. / Pishchevaritel'nye fermenty v zheludochno-kishechnom trakte, pochke, pecheni i selezenke pri razlichnykh funktsional'nykh sostoianiiakh.

A wide range of digestive enzymes with different cellular location (membrane, intracellular, Lysosomal) was determined in gastrointestinal organs (stomach, duodenum, jejunum, ileum, colon) as well as in undigestive organs (liver, kidney, spleen) in normal conditions and in altered functional states (fasting, refeeding). High levels of peptidase activity was noted in undigestive organs and the colon as compared to that in the small intestine. Adaptive responses were (revealed not only for a number of membrane enzymes but also for intracellular ones including those in undigestive organs.

[The enzyme-transport characteristics of the small intestine of rats during aging]. / Fermentativno-transportnye kharakteristiki tonkoi kishki krys pri starenii.

Ageing was shown to be accompanied by changes of the activity levels of the small intestine's carbohydrases, dipeptidases, and alkaline phosphatases. The changes occurred both under normal conditions and after operations on the small intestine. In ageing, the small intestine's capacity for the homeomorphosis decreases irrespective of either increase or decrease in the functional loading. The age involution of the gastrointestinal tract is followed by disturbances not only in hydrolytic processes but in transport those as well: particularly deceleration of glucose accumulation in preparations of the rat intestine mucose. Regulatory properties of some enzymes were changed, too, in old rats.

[The hydrolases of the mucosal, submucosal and muscular layers of the small intestine and their functions]. / Gidrolazy mukoznogo, submukoznogo i myshechnogo sloev tonkoi kishki i ikh funktsii.

Proceeding from the newly obtained evidence on the distribution of digestive enzymes in mucosal, submucosal and muscular layers of the small intestine in rats, a hypothesis has been formulated: in addition to the enterocyte enzyme complex forming the epithelial barrier, there seems to exist a postepithelial barrier formed by the enzymes localized in subepithelial structures. The efficiency of this second barrier was manifested by the study of the peptide hydrolysis and transport using everted intact and de-epithelialized intestinal sacs.

[The characteristics of the properties of the membrane and cytosol peptidases of the enterocytes in different animal species]. / Kharakteristika svoistv nekotorykh membrannykh i tsitozol'nykh peptidaz énterotsitov raznykh vidov zhivotnykh.

Studies have been made on some of the properties of glycylleucyn- and leucylglycyne dipeptidases from the membrane and cytosol fractions of enterocytes of mice, rats and rabbits. Differences in cellular distribution of these enzymes in the species investigated were found. These enzymes also differ in their thermostability and the reaction to the effect of an inhibitor, 1,10-phenantrolyne. Presumably, these peptidases are presented by different enzymes which are subjected to separate genetic control.

[Digestive enzymes in the epithelial and subepithelial layers of the small intestine in different strains of rats]. / Pishchevaritel'nye fermenty v épitelial'nom i subépitelial'nykh sloiakh tonkoi kishki u krys raznykh linii.

Studies have been made on the activity of various digestive enzymes and their distribution between the mucosal, submucosal and muscle-serosal layers of the small intestine in Wistar and Sprague-Dawley rats. Three groups of the enzymes were found, their activities being maximal either in the mucosal, or in muscular layers, or being evenly distributed between three intestinal layers.