[Change in localization of cellular vesicular apparatus during differentiation of myoblasts into myotubules in cell culture].

The study of changes in the intracellular processes during differentiation of myoblasts into myotubules is of great importance for understanding several fundamental problems of cell biology. At first, this concerns the spatial organization of vacuolar apparatus that reflects the alterations in the properties of cell membranes, cytoskeleton elements and dynamics of vesicular transport in the course of differentiation. The distribution of acidic membrane organelles (lysosomes, late endosomes, Golgi cisternae) during the myotubule formation was revealed.

[Untargeted quantum dots in confocal microscopy of living cells].

The problem of non-specific binding of quantum dots (QDs) with cells is very important but not fully understood taking into account the possible application of QDs in medical and fundamental studies. The interactions of untargeted CdSe/ZnS QDs with isolated frog muscle fibres, HeLa cells and J774 cells were investigated. The observations were performed on living cells using laser confocal microscopy (Leica TCS SL).

[AO distribution and fluorescence spectra in myoblasts and single muscle fibres].

Using spectral scanning regime of Leica TCS SL confocal microscope, acridine orange (AO) fluorescence spectra in nuclei and cytoplasms of living myoblasts L6J1 and frog single muscle fibres have been studied. AO fluorescence spectra in salt solutions dependent on free AO concentrations and in AO complexes with DNA have also been obtained for comparison. Myoblasts nuclei fluoresced in green spectral region with maximum at approximately 530 nm (corresponding AO monomers fluorescence), nucleoli fluoresced most brightly.

[Confocal-microscopic study of skeletal muscle fibre membrane organelles during Zenker's (spreading) necrosis].

The changes of T-system and cellular acidic organelles during spreading (Zenker's) necrosis of frog skeletal muscle fibres have been investigated using laser confocal microscopy and several vital fluorescent dyes acridine orange, RH 414, DiOC6(3), rhodamine 123, fluorescein dextran. The formation of numerous vacuoles as a result of local T-system swelling is most characteristic for initial steps of Zenker's necrosis. Vacuoles can attain tens microns in length.

Acridine orange accumulation in acid organelles of normal and vacuolated frog skeletal muscle fibres.

The spatial distribution of acid membrane organelles and their relationships with normal and vacuolated transverse tubules has been studied in living frog skeletal muscle fibres using confocal microscopy. Acridine orange (AO) was used to evaluate acid compartments, while a lipophilic styryl dye, RH 414, was employed to stain the membranes of the T-system. AO accumulated in numerous spherical granules located near the poles of nuclei and between myofibrils where they were arranged in short parallel rows, triplets or pairs.

[Effect of alkaloid sanguinarine and a pharmaceutical preparation ukrain on modulation of vesicular membrane fusion and actin cytoskeleton of macrophages].

A study was made of modulations of lysosome-phagosome fusion process and of fibrillar actin content in mouse peritoneal macrophages by an antitumor alkaloid sanguinarine and a derivative drug Ukrain. In addition, effects of these substances on in vitro polymerization of monomeric globular actin from rabbit muscle were investigated. Sanguinarine and Ukrain stimulated lysosome-phagosome fusion and increased the content of polymerized fibrillar form of actin in mouse macrophages.

[Localization of acid organelles in frog skeletal muscle fibers].

By means of fluorescent and phase-contrast microscopy the distribution of acid membrane organelles in normal and vacuolated frog skeletal muscle fibers has been studied. The vacuolation of the T-system was produced by loading and subsequent removal of glycerol (80-110 mM), or it appeared as a result of Zenker's necrosis. Acridine orange (AO) was used as a marker for acid intracellular compartments.

Sensitivity of lysosomal enzymes to the plant alkaloid sanguinarine: comparison with other SH-specific agents.

The influence of the benzo[c]phenanthridine alkaloid sanguinarine on some lysosomal enzyme activities was investigated. Sanguinarine inhibits lysosomal hydrolases in homogenates of cultured mouse fibroblasts. After incubation of mouse fibroblasts in culture with 100 microM sanguinarine an approximately 50% decrease in the activities of N-acetyl-beta,D-glucosaminidase (NAGA), beta-galactosidase (GAL), arylsulfatase and acid lipase was observed.

[Effects of cationic vectors complexed with plasmid DNA on the phagosome-lysosome fusion in murine peritoneal macrophages and J744 macrophages].

Polyethylenimine (PEI) and cationic polypeptides complexed with plasmid DNA are the most efficient nonviral vectors for gene therapy. It is believed that endocytosis is the major pathway for cell entering by PEI/DNA or cationic peptides/DNA complexes. Effects of plasmid DNA complexed with PEI, poly-L-lysine (PLL), poly-D-lysine (PDL) and polyarginine (PA) on the phagosome-lysosome fusion (P-LF) were studied in murine peritoneal macrophages and J774 macrophages.

[Effect of polyamine synthesis inhibitors separately and in combination with epidermal growth factor on fusion of lysosomes with phagosomes and F-actin level in mouse peritoneal macrophages].

Effects of polyamine (PA) synthesis inhibitors--alpha-difluoromethylornithinchloride (DFMO) and alpha-methylornithinchloride (MO)--separately or in combination with the epidermal growth factor (EGF)--on lysosome-phagosome fusion (P-LF) and F-actin content in murine peritoneal macrophages were studied using fluorescent dye Acridine orange for lysosome labelling, FITC-phalloidin for F-actin, and yeast cells as a target. DFMO and MO significantly inhibited P-LF and decreased F-actin content in murine peritoneal macrophages. A combination of DFMO and MO with EGF failed to inhibit P-LF or to decrease F-actin content in these cells.

Effects of some biologically active compounds on phagosome-lysosome fusion in peritoneal macrophages of mice.

Effects of biologically active compounds bilirubin (BR), farmorubicin (FR), and chelerythrine (CR) on phagosome-lysome (P-L) fusion in mouse peritoneal macrophages were studied using fluorescent dye acridine orange as lysosomal labelling and yeast cells as target. It was found that all three compounds tested enhanced P-L fusion. To investigate mechanisms of these effects, changes in fluidity of rat liver lysosomal membranes under influence of BR, FR and CR were studied by measuring fluorescence intensity, lifetime, and polarization of DPH or TMA-DPH incorporated in isolated rat liver lysosomes.

[Effect of some DNA-intercalators and antioxidants on the phagosome- lysosome fusion and F-actin content in murine peritoneal macrophages].

Effect of DNA-intercalators ethidium bromide (EB, 0.005 and 0.015 mM) and dimidium bromide (DB, 0.

[The effect of biologically active compounds on lysosome fusion with phagosomes and the F-actin content in mouse peritoneal macrophages and on the status of the lysosomal membranes in mouse hepatocytes].

Effects of biologically active compounds bilirubin (BR, 0.1 and 0.2 mM), chelerythrine (CR, 0.

[The vacuolar apparatus and membrane fusion in the cell].

Current literature on the structure of vacuolar apparatus and its involvement in the process of intracellular transport has been reviewed. Modern views on endocytosis and its particular steps are described. Special attention is paid to one of important steps of endocytosis-the phagosome-lysosome fusion, its disturbance under the action of pathogenic microorganisms, its inhibition and stimulation by some chemical factors and biologically active compounds.

[The effect of different antitubercular agents on phagosome fusion with lysosomes, on the F-actin content in mouse peritoneal macrophages and on G-actin polymerization in vitro].

Effects of various antituberculosis remedies (ATR)--isoniazid (INA), saluzid (SA), streptosaluzid (SS), ethambutol (EB), sodium para-aminosalicylate (SPAS) on phagosome-lysosome (PL) fusion, on F-actin content in mouse macrophages and on G-actin polymerization in vitro were studied. The ATR of choice have been shown to stimulate the PL fusion. INA (0.

[The effect of chemical agents on lysosome fusion with phagosomes and on the F-actin content in murine peritoneal macrophages].

The influence of natural and synthetic polyamines, phalloidin, cytochalasin D, vinblastine, colchicine, puromycin, chlorpromazine, urea, glutaraldehyde, and ethanol on the phagosome-lysosome fusion and the content of F-actin in murine peritoneal macrophages has been studied. Fluorescent phallotoxin FITC-phalloidin was used to stain F-actin. Natural polyamines (spermine, spermidine, putrescine), phalloidin, ethanol (0.

[The effect of diamines on the process of lysosome fusion with phagosomes in mouse peritoneal macrophages].

Diamines (DA), characterized by a general formula H2N-(CH2) n-NH2 in which n varies from 2 to 10, inhibit the phagosome-lysosome fusion in murine peritoneal macrophages. The DA concentration was 0.2, 0.

[The effect of polyanion, cationic and anionic dyes and nonelectrolytes on phagosome fusion with lysosomes in mouse peritoneal macrophages].

Polyanion (mannansulphate), cation dyes (Toluidine blue, Nile blue), anion-dye (Trypan blue) also non-electrolytes (urea, glutaraldehyde) were found to inhibit the phagosome-lysosome fusion in murine macrophages. The mechanism of this effect is discussed.

[The effect of polyamines on lysosome fusion with phagosomes in mouse peritoneal macrophages].

The influence of polyamines on the phagosome-lysosome fusion in murine peritoneal macrophages and on polymerization of G-actin from the rabbit muscle in vitro has been studied. Both natural polyamines (spermin, spermidin, putrescin) and synthetic phenyl derivates of polyamines (3,3'-diaminobensidin, 1,5-naphtalin diamine, 4,4'-diaminodiphenilmetan, dancylcadaverin) were used. Unlike the phenyl derivates of polyamines and putrescin, spermin and spermidin stimulate the phagosome-lysosome fusion to induce G-actin polymerization.

[Decreased G-actin content in cells at injury].

The content of G-actin was measured in aqueous extracts of rat macrophages and human lymphocytes at hyperthermia and hypoxia. The G-actin content in altered cells decreases the greater the stronger the injury. This decrease correlates well with the data on visual estimation of cell light diffusing.

[Epsilon-aminocaproic acid inhibits the propagation of damage along the nerve fiber].

An inhibitor of proteinases--epsilon-aminocaproic acid--inhibits the propagation of destruction along the muscle fiber isolated from frog m. iliofibularis. It is assumed that generalization of the injury is hampered by a protein precipitate formed at the site of the injury, which is preserved due to inhibition of proteinase activity.

[Effect of nonelectrolytes on the polymerization of G-actin].

The non-electrolytes--urea, thiourea, sucrose, glycerin, polyethylendioxid, glutaraldehyde--inhibit polymerization of G-actin in vitro. The results are discussed in association with the capability of some non-electrolytes preventing colloid reactions of alterated protoplasm and increasing the stability of cells to injuring agents.

[NADPase and NADase in the peritoneal macrophages of mice].

Murine peritoneal macrophages are able to hydrolyse NAD+ and NADP+. The NADPase activity exceeds that of NADase by 22-24%. The pH optima for both the enzymes are, respectively, 6.

[Synthesis and breakdown of pyridine nucleotide coenzymes in the cell nuclei of guinea pig kidneys in diphtheria intoxication].

The effect of diphteria toxin on the synthesis and degradation of NAD+ and the hydrolysis of NADP+ in the nuclei of guinea pig kidney were studied. Treatment of animals with diphteria toxin (DT) results in considerable reduction of NADpyrophosphorylase activity, which starts 12 hours after incubation and is minimal (50% of that of the control animals) 18 hours after it. During this time interval DT does not affect the activity of NADase and decreases that of NADPase in the nuclei.