On the direction of the diffusional electric field in a mucous layer.

A simple model of the mucous layer is used to illustrate the complex relationship of the diffusional electric field direction in the layer and parameters of the latter. It is shown that the field direction may depend not only on the ratios of mobile microion diffusivities but also on the characteristics of the layer (carboxylic group concentration and dissociation constant). The electric field direction is also shown to vary across the layer under appropriate conditions. The results are used to interpret the electrophoretic mechanism of the transport of macromolecules across the mucous layer on the surface of the digestive tract wall.

[So-called constancy of chyme composition]. / O tak nazyvaemom postoianstve sostava khimusa.

Study of the chyme composition in different phases of digestion at different levels of the small intestine showed the composition to be stabilized enough in respect to the water and electrolytes contents as well as the main nutricious substances. Gradual increase in concentration of the main NSs occurs in the advancing chyme. The data obtained suggest that the constancy of the chyme composition is only valid in respect to the water and electrolytes regardless of their unequal contents in the food.

[Phenomenon of formation of structures in the dense fraction of the enteric milieu when its pH is changed]. / O fenomene obrazovaniia struktur plotnoi fraktsii énteral'noi sredy pri izmeneniiakh ee pH.

Morphological study of the dog duodenum and ileum contents revealed that the food particles of less than 2 mm size constituted not more than 30% of the total volume of the chyme dense fraction. The main part of the dense fraction consists of the gel structures precipitating in the enteral milieu during changes of its pH due to acid content of the stomach. Histochemical reactions of these structures reveal presence of mucopolysaccharides, proteins and lipids. As the surface of these structures is able to adsorb the digestive enzymes, the intensive digestion of small food particles seems to be due to an increase of the enzyme hydrolysis occurring on the chyme dense fraction structures which are being formed during changes of the enteral milieu pH.

[Distribution of lipids and lipolytic activity between the solid and liquid phases of an enteral medium]. / Raspredelenie lipidov i lipoliticheskoi aktivnosti mezhdu plotnoi i zhdikoi fazami enteral'noi sredy.

Data on the lipid and lipase activity distribution between the solid and liquid phases of the enteric coacervate formed from pancreatic secretion at lower pH is described. It is established that after coacervation the amount of lipids available for extraction increases, the lipase activity of sample grows, the major part of the lipase activity becomes localized in the solid phase. The solid phase is rich in lipids, the content of which pH dependent. A hypothetical mechanism of these phenomena and some computations are presented.

[Enzymes in the mucosal layer of the small intestine]. / Fermenty sloia slizi tonkoi kishki.

It has been demonstrated by the methods of histochemical and biochemical examination of the activity of the enzymes that the mucus layer covering the small intestinal wall contains active enzymes (alkaline phosphatase, leucin aminopeptidase IV, saccharase, lactase) and pancreatic enzymes (alpha-amylase and trypsin). Emphasis is laid on the enrichment of the mucus layer with pancreatic enzymes as compared with small intestinal juice. A hypothesis has been advanced according to which the mucus layer undergoes degradation of polymeric and oligomeric substrates, which plays a physiological part in the digestion of nutritive substances and protection of the internal medium against immunoactive biopolymers. The digestion occurring in the mucus layer is proposed to be called mucus digestion.