Biomedical subjects
Publications and source records attributed to M V Shubin.
Efflux of Ca2+ ions from liposomes after peroxidation of their lipids was studied using fluorescent assay with chlorotetracicline. It was shown that products of lipid peroxidation disturbed the stability of liposome membranes and increased their permeability for Ca2+ ions.
Artificial vesicles, liposomes, were prepared from the total fraction of phospholipids of rat liver mitochondria. Electron microscopy showed that the structure of liposomes depended on cation composition of the medium in which they were formed. Fluorescence of chlorotetracycline increased in the suspension of liposomes loaded with Ca+2 due to the formation of Ca+2-chlorotetracycline-phospholipid membrane complex. Incubation of liposome suspension with phospholipase A in the presence of EDTA resulted in a decrease of chlorotetracycline fluorescence indicating a break of the integrity of liposome membranes and Ca+2 efflux.
Temperature effect on changes in calcium ion transport and activity of Ca-ATPase of sarcoplasmic reticulum vesicles (SRV) was studied. Several temperature intervals of the change of SRV functional activity parameters were found: 8-12 degrees C-beginning of accumulation of SRV Ca2+, 12-19 degrees sharp activation of Ca2+ accumulation, 27-32 degrees-activation of passive yield, 36-43 degrees-reversible change of the activity of the accumulation system and activation of Ca yield, 48 degrees and higher--irreversible denaturation of transport Ca-ATPase. Coincidence of temperature intervals of SRV structural reconstructions, detected by means of fluorescent probes and functional changes points to a close relationship between structural reconstructions and functional responses of biological membranes.