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Biomedical subjects

A M Ugolev

Publications and source records attributed to A M Ugolev.

At least 73 records · Page 4Linked to original sources
PubMed1982

[Role of basolateral and apical respiration in the active transport of glucose and maltose in different segments of the small intestine under different functional conditions].

The active transport of free glucose and glucose released in membrane hydrolysis involves oxygenation of mucosal and seroseal surfaces as well as bilateral one. The glucose accumulation against the electrochemical gradient increases in transition from fasting to satiety. The data obtained suggest a hypothesis stating that enterocytes and, probably, other functionally polarized cells have not a single (basolateral) but double types of the cellular respiration: the apical as well as the basolateral ones. In addition to diffusion exchange of O2 and CO2 between the blood and the basolateral surface of cells, the gas exchange is supposed to occur at the apical surface as well. The O2 transport to this particular surface of cells can be based on the Na+ microcirculation. The interrelationship between the apical and basolateral types of respiration was shown to depend on the functional condition of the organism (satiety or hunger).

Animals↗
PubMed1982

[New data on the mechanisms of glucose transport in the small intestine based on an analysis of the role of serous-mucous flows].

The transport of glucose, other monosaccharides and disaccharides in the rat small intestine has been studied under the condition of a predominance of serosal-to-mucosal (SM) flows over mucosal-to-serosal (MS) ones. A dependence has been found of the efflux of glucose into the serosal solution on the duration of incubation, starting glucose concentration in the serosal solution, intestinal segment under study (proximal-distal gradient), action of glucose transport inhibitors (phlorizin, absence of Na+ in the incubation medium, anoxia) and temperature. In this paper, the hypothesis on entero-hematic circulation has been proposed, according to which recycling of glucose is one of the important manifestations of processes of microcirculation of substances between blood and the intestine.

Animals↗
PubMed1980

[New method of studying membrane hydrolysis and transport as well as metabolic processes in the small intestine in vitro (everted small intestinal sac with bilateral oxygenation)].

The effect of bilateral oxygenation (from mucosal and serosal surfaces) of the small intestinal preparation on glucose accumulation has been investigated. It has been demonstrated that such a type of oxygenation significantly (two fold) increases the absorption of glucose as compared to that under oxygenation only from musocal surface. This data sugested that oxygenation from serosal site of the small intestine had an important role in the transport of free glucose.

Animals↗
PubMed1979

[Substrate and parasubstrate regulation of physiological processes at various levels of the organization of living systems as illustrated by examples of the regulation of appetite, of the specific dynamic action of food and of the inhibition of processes of absorption].

It was demonstrated that in the organism of higher animals the adaptation regulation of food uptake and nutrient absorption and transport comprises, in addition to the classic mechanisms of substrate regulation, specialized non-substrate and parasubstrate mechanisms which control the uptake of food and other substrates at all three levels (organosystemic, organic and cellular). As to the organosystemic level, it was observed in duodenectomized rats that appetite inhibition is produced not only by a stimulation of the receptors and by an increase in the concentration of the food substrates and of the metabolites in the blood, but also by one of the intestinal appetite-inhibiting hormones, arenterin. As to the organic level, it was evidenced that the enzymatic and transport functions of the small intestine and the numerical composition of the enterocyte population in the different segments are determined by the substrate load on the respective areas of the small intestine as well as by the blood and chyme-mediated intersegmental reactions in the small intestine. As to the tissular and cellular levels, the possibility of a regulation of the enzymatic and transport systems of the microvilli by means of substrates contained in the mucous membrane of the small intestine and endogenous substances (permein and antipermein) was evinced.

Adaptation, Physiological↗
PubMed1979

[Regulatory properties of the intestinal enzymes of higher and lower animals as an adaptation mechanism in digestion and absorption].

It is shown that certain key enzymes in membranous digestion (alkaline phosphatase, peptidase, gamma-amylase) are allosteric and ensure the autoregulation and the homoeostasis of the final stages of hydrolysis and of the initial stages of nutrient transport. This mechanism was evidenced not only in vertebrates (mammals, birds, fishes), but also in invertebrates (drosophilae). The comparison of the triton and trypsin forms of the enzymes permitted to locate centres of regulation in the hydrophobic parts of amphipathetic enzymes (as illustrated by the examples of alkaline phosphatase and gamma-amylase of of the rat and of the drosophila). A considerable variability of the regulatory characteristics of the enzymes under investigation was demonstrated in the different varieties of drosophila. The authors present a hypothesis on the role of the regulatory properties of digestive enzymes in the physiology and the pathology of the digestive and transport systems of the small intestine.

Adaptation, Physiological↗