[Changes in the brain neuraminidase activity under the action of tsiklozil and amizil]. / Izmenenie aktivnosti neiraminidaz golovnogo mozga pri deistvii tsiklozila i amizila.

The effect of cyclozyl and amizyl on the activity of soluble and membrane-bound neuraminidase of the rat brain is studied in the in vivo and in vitro experiments. Within 60 min after subcutaneous injection of cyclozyl in a dose of 0.5 microgram/kg of body weight the activity of soluble neuraminidase decreased by 45.5% whereas the activity of membrane-bound neuraminidase remained the same. In the experiments in vitro the activity of both enzyme forms did not change when the content of cyclozyl and mixture of general gangliosides in the incubation media was 2.0, 20.0, and 200.0 micrograms. Amizyl (2 micrograms) in the presence of general gangliosides increased the neuraminidase activity whereas in the presence of disialoganglioside GD1b reduced the activity. Various lipids (phospholipids, phospholipids + cholesterol, cerebroside + sulfatides) surrounding the enzyme exerted different effect on the activity of both neuraminidase forms. Thus we suggest active interaction of the system "gangliosides-soluble and membrane-bound neuraminidase" with M-cholinolytics (cyclozyl and amizyl) and important role of this "substate-enzyme" system in M-cholinoreceptor functioning.

[Control of cell multiplication in vitro. V. The dependence of cell multiplication on the ganglioside content]. / Kontrol' razmnozheniia kletok in vitro. V. Zavisimost' razmnozheniia kletok ot soderzhaniia v nikh gangliozidov.

The concentration and composition of gangliosides in the cells of L-line and its clones--L-2 and Lebr 1/1, with values of saturation densities being 0.9, 1.6 and 3.2 X 10(5) cells/mc2, respectively, were compared. The transition of populations in the stationary growth phase was shown to be accompanied by an increment of ganglioside concentration and accumulation of di- and three-sialogangliosides. The data obtained are discussed in connection with the previously published results about changing intracellular cAMP content and conA-mediated agglutination at density-dependent growth inhibition L-cell variants.

[Glycoproteins and glycolipids in intercellular interactions]. / Rol' glikoproteinov i glikolipidov v mezhkletochnykh vzaimodeistviiakh.

Glycoproteins and glycolipids as important constituents of the extracellular matrix are considered in the present review. Their role in the processes of cell-to-cell contacts, control of cell proliferation and neoplactic transformation, are discussed. A glycosyltransferase-acceptor model of cellular recognition is also given.

[Metabolic activity of the N-acetylneuraminic acid of the principle gangliosides of the brain]. / Metabolicheskaia aktivnost' N-atsetilneiraminovoi kisloty osnovnykh gangliozidov mozga

The turnover rate of N-acetylneuraminic acid of brain gangliosides (GT1, GD1b, GD1a, GM1) was studied following the injection of 2-14C-acetate. The specific activity of N-acetylneuraminic acid in GD1a and GM1 was found to be higher than in GD1b. The administration of aminasine reduced the specific activity of N-acetylneuraminic acid whereas chlorhydrate increased that of major brain ganglosides.