Structural and functional analysis of glucose absorption mechanisms in the rat small intestine in vivo.

The absorption of glucose (free, and released from membrane hydrolysis of maltose) and water in the isolated loop of the rat small intestine was studied in chronic experiments. Even at maximum glucose (75 mmol/l) or maltose (37.5 mmol/l) concentrations the rate of glucose transfer by solvent drag and by diffusion did not exceed 13% and 25%, respectively, of the total rate of glucose absorption.

[Isolated enterocytes as an object of functional morphology].

Morphological examination of isolated enterocytes obtained-from the rat jejunum initial region by mechanical method after the previous treatment with ethylendiamintetracetic acid disodium salt included staining with hematoxylin, carmin and janus green. Histochemical reaction to alcaline phosphatase, succinate dehydrogenase, lactate dehydrogenase, ATP-ase and glycosaminoglycans were performed. Significant resemblance between the main cytological and cytochemical characteristics of the isolated enterocytes and those of the intestinal epithelium was demonstrated.

[An analysis of the structural characteristics of the tight junction of the enterocytes of the rat small intestine during nutrient absorption (immunoelectron microscopic research)].

To analyze structural changes of intercellular relationships of the enterocytes during glycine, glucose, and triolein absorption the structural and immunocytochemical methods of electron microscopy were used. The study was carried out on the proximal part of the rat small intestine in acute and chronic experiments. In the acute ones glucose or glycine solutions (both of 10 and 40 mM) or triolein emulsion (0.

[Proteases of the large intestine].

The large intestine was found to reveal an obvious activity of various aminopeptidases and genuine dipeptidases in dogs and in humans. A dipeptidase was found specific by its independence of the C-terminal configuration of the peptide. This peptidase in an intrinsic membrane protein.

[Circadian rhythm of intestinal glucose absorption in fasting and fed rats].

Under conditions of chronic experiment the circadian cycle of glucose transport was determined. An isolated proximal area of the small intestine was perfused by glucose, fructose, medical bile and Ringer's solutions in various intervals of the 24 hour period. The circadian cycle of glucose absorption is disturbed in the fasting rats.