Adaptive and proapoptotic reactions of cardiomyocytes to stress of the endoplasmic reticulum play a fundamental role in the development and progression of cardiovascular diseases and in the nearest future may become effective therapeutic targets. Since the endoplasmic reticulum is the main source of free oligosaccharides (FOS) — unbound structural analogues of glycans of glycoconjugates, their structures can reflect a state of this cell organelle. Moreover, some fractions of FOS might represent a status of lysosomes and endosomes. FOS penetration from cells into blood and urine makes them prospective markers of cell stress in biological fluids.
The objective of the work was a characterization of FOS in blood plasma obtained from patients with cardiac failure before and after standard treatment. Chromatographic profiles of FOS composed of 4–12 monosaccharides were obtained and analyzed for quantitative and qualitative differences between the samples. After plasma deproteinization and FOS purification the oligosaccharides were labelled with anthranilic acid, separated into the neutral and charged with QAE Sephadex chromatography and analysed using high-performance liquid chromatography.
After treatment, the spectrum changes were observed in neutral fractions of FOS with the restoration of dominant concentrations of the same main peaks as in the control profile. The depth of these changes had individual features but a full profile recovery was not observed since the concentrations of the peaks marked the cardiac failure at this stage of the treatment were still significantly higher than in the control profile. There was no impact of the treatment on the charged fraction of FOS. That might indicate a stress prolongation of endosomal-lysosomal system in spite of the therapy. The study of FOS of blood plasma is a new field allowing an evaluation of an organism state at the level of the cell organelle functional status.