[Regulation of mechanical stability of erythrocytes by serum immunoglobulins]. / Reguliatsiia mekhanicheskoi prochnosti éritrotsitov immunoglobulinami plazmy krovi.

Autologic plasma protects human erythrocytes from hemolysis induced by their suction through glass microfiber filters. The protective effect is related to the protein fraction with molecular mass above 100 kD and reproduced by gamma-globulin. The action of proteins is abolished after heating the erythrocytes above 45 degrees C as well as in the presence of galactose and ribose but not glucose, mannose and lactose. It is suggested that an increase in mechanical stability of erythrocytes is caused by interaction of immunoglobulins with glycoproteid and glycolipid membrane receptors and mediated by the changes of structural state of the cytoskeleton.

[Mechanism of brain Na,K-ATPase activation by adrenaline]. / Issledovanie mekhanizma aktivatsii Na,K-ATPazy mozga noradrenalinom.

Norepinephrine stimulates Na, K-ATPase from rat brain homogenates at concentrations of 10(-4)--10(-5) and 10(-7)--10(-8) M. A low concentration maximum is observed after 48 hrs of incubation at -20 degrees C and is not changed by the addition of alpha-tocopherol, glycerol and MAO inhibitor ipraside. The maximum observed at the mediator concentration equal to 10(-4)--10(-5) M is eliminated after treatment with EGTA. At all concentrations of norepinephrine the enzyme stimulation is removed by the alpha-adrenoblocker phentolamine. The activated enzyme reveals lower sensitivity to Ca2+ induced inhibition. The role of Ca2+ and conformational state of the membranes in the realization of the remote effect on the adrenoreceptor-Na, K-ATPase system is discussed.

[Structural rearrangements in membranes induced by anesthetics]. / Strukturnye perestroiki membran, indutsiruemye anestetikami

Studies were carried out on the effects of anesthetics on the stability of membranes to sodium dodecylsulfate and trypsin. The initial rate of membrane desintegration by detergent evaluated by light scattering with stopped flow method was increased in the presence of ethanol, propanol, benzyl alcohol, procain-amide (erthrocyte membrane) and chlorpromazine (rat brain synaptosomes). Concentrations of anesthetics which correspond to half of the maximum effect were very close to that of blocking the action potential and inducing 50%--antihemolysis. Alcohols and procaine at anesthetic concentrations inhibited proteolysis of isolated erythrocyte membranes but were without effect on their ultrasonic fragments. Increase of membrane desintegtation rate is interpreted as structural rearrangements of membranes with the weakening of detergent sensitive intermolecular interactions. Proteolysis inhibition of ghosts but not the gragments indicates against the participation of the basic func of proteins in the structural membrane rearrangements.