[Changes in the brain neuraminidase activity under the action of tsiklozil and amizil]

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.