Bioactive peptide isolated from casein phosphopeptides promotes calcium uptake in vitro and in vivo

A monomeric peptide isolated from casein phosphopeptides promoted calcium uptake in cells via the transcellular pathway and was beneficial for bone calcification in rats.

EFFECT OF PROBIOTIC BACTERIA AND LIPOPOLISACCHARIDES ON EPITELIOCYTES TIGHT JUNCTIONS OF RAT JEJUNUM

Aim. The present study has been undertaken with the main objective the influence of probiotic bacteria Lactobacillus plantarum 8 РАЗ and Escherichia coli M17 and lipopolysaccharide on the ultrastructure of enterocytes tight junctions of mucous membranes of rat jejunum. Materials and methods. The study was carried out on E. coli lipopolysaccharide (Sigma-Aldrich, Germany) and probiotic bacteria L. plantarum 8PA3 and E. coli M17. Male Wistar rats were used. A comparative analysis of the ultrathin structure of enterocytes and tight junctions were carried out by successive incubation of rat jejunum with probiotic bacteria L. plantarum 8PA3 and E. coli Ml 7, with lipopolysaccharide and a complex of bacteria with LPS. Results. The effect of L. plantarum 8PA3 on the mucosa of rats jejunum on a number of characters was similar to E. coli Mil. It manifested by preservation of the intact structure of the intercellular space and tight junctions. At the same time, hollow spherical inclusions with fragments of bacteria surrounded by membranes detected in the cytoplasm of enterocytes testified to the possibility of penetration of probiotic bacteria through the mucous membrane of the jejunum by a transcellular pathway With simultaneous action on enterocytes of rats jejunum of probiotic bacteria and lipopolysaccharide complex no destructive changes in the structure of dense contacts were observed, however, in a significant number of cases, bacterial cells were found in the intercellular space next to the goblet cells. Conclusion. A similar effect of Gram-positive bacteria L. plantarum 8PA3 and Gram-negative bacteria E. coli Ml 7 and their complexes with lipopolysaccharide on the jejunum epitheliocytes was revealed. Morphological analysis showed that lipopolysaccharide might influence on parasel-lular transport by probiotic bacteria. In the absence of LPS, probiotic bacteria can possibly penetrate the mucosa of rats jejunum by a transcellular pathway.