[Hemostasis system and inflammation acute-phase proteins in thrombogenic pathologies].

New knowledge concerning the role of inflammation in activation of fibrinolysis and in discoordination of its components interaction has been presented in the review. Considerable attention was given to molecular mechanisms of the haemostatic protein involvement in the acute phase of inflammation. An analysis of their level changes according to inflammation state has been proposed for thrombogenic risk assessment. Abundant consumption of plasminogen in situ as a result of coagulation induced by moderate level of inflammation is the first critical point in thrombus formation. Activated protein C leakage during severe inflammation is another trigger of thrombogenesis leading to possible death.

[Mechanism of fibrinolysis and thrombolytic therapy]. / Mekhanizm fibrynolizu i trombolitychna terapiia.

The thrombolytic treatment with plasminogen activators, such as physiological tissue-type plasminogen activator (t-PA), suffers from a number of significant limitations. There is a resistance to reperfusion and acute coronary reocclusion. The peculiarity of t-PA and one-chain urokinase treatment is their using in very high doses. Thus the process of thrombolytic therapy is proceeding with a deviation from the fibrinolytic mechanism, which is needs of a little quantity of tissue-type plasminogen activator and provides the physiologic thrombolysis without systemic complication. The estimation of this disaccordance suggests, the possible reasons of these complications.

[Solubilization of Mg2+-dependent Ca2+-activated ATPase of brain microsome fraction].

Mg2+-dependent Ca2+-activated ATPase (Mg2+, Ca2+-ATP-ase) of microsome fraction from grey matter of great cerebral hemispheres of cattle is activated by 0.1% solution of digitonin. Simultaneously 30-60% of initial fraction protein is extracted, respectively, with 0.1-0.3% concentrations of digitonin. The Mg2+- and Mg2+, Ca2+-ATPase activities manifest in solubilized protein. The maximal solubilization of both enzymes is reached when treating the fraction of brain microsomes with 0.3% solution of digitonin, the Mg2+, Ca2+-ATPase activity is not manifested in the 0.2% digitonin extract of this fraction. The Mg2+, Ca2+-ATPase activity is not always manifested in the 0.4% digitonin extract of the sediment which was obtained after extracting the initial fraction with 0.2% solution of digitonin. Addition of 0.2% extract to it causes manifestation or increase of the Mg2+, Ca2+-ATPase activity. Thus, minimum two components which are extracted by detergent in different concentrations or one of the extracted components which is an activator of solubilized Mg2+, Ca2+-ATPase may be necessary for manifestation of this activity in the solubilized components of the fraction of brain microsomes. The membrane components extracted with digitonin possess evidently a small molecular weight as they compose 7.5% polyacrylamide gel in which 0.4% digitonin extract of the brain microsome fraction is divided into 7-8 electrophoretic zones.

[SH-group and Mg2+-dependent Ca2+-activated ATPase activity of the microsome fraction of the brain]. / SH-grupy i Mg2+-zalezhna Ca2+-aktyvovana ATF-azna aktyvnist' fraktsiï mikrosom mozku

Mg2+-dependent Ca2+-activated ATPase of microsoma fraction from the grey matter of cerebral great hemispheres determined after the preliminary treatment of the preparation with 0.1% digitonin, while preserved in the medium with 10 mM mercaptoethanol for seven days at a temperature of 4-6 degrees C is inactivated by 10-15% and approximately by 50% while preserved without mercaptoethanol. Mercaptoethanol does not make reactivating effect. SH-reagents at definite concentrations completely inhibit the activity of Mg2+, Ca2+-ATPase. Half-maximum inhibition of the enzyme is reached with the salirgan, p-CMB and NEM concentrations of 5-10(-6) M, 5-10(-6) M and 5-10(-3) M, respectively. Mg2+-ATPase is not suppressed completely, and at high concentrations of SH-reagents the residual activity is 1.3 muM of Pi per 1 mg of protein in 1 hr. ATP in the concentrations optimal for manifestation of Mg2+, Ca2+-ATPase (3 mM) efficiently protects the enzyme from the inactivating effect of NEM. This gives reasons to suppose that the active centre of Mg2+, Ca2+-ATPase contains an SH-group. The quantity of SH-groups readily accessible of the Ellman reactive in the initial preparation of the brain microsomes is 45 + 2.0 nM per 1 mg of protein and in the preparation dissolved in 2.5% sodium dodecyl sulphate, 110 + 7.8 nmM per 1 mg of protein. In the presence of 0.1% digitonin the quantity of SH-groups of the preparation is 55 + 3.5 nM per 1 mg of protein, simultaneously such treatment of detergent results in manifestation of Mg2+, Ca2+-ATPase activity. An inactivating effect of SH-reagents and the protective effect of ATP indicate similarity of the enzyme under study to Mg2+, Ca2+-ATPase of sarcoplasmatic reticulum.

[Solubility of the Mg2+-dependant Ca2+-activated ATPase fraction of the plasma membranes of synaptosomes]. / Soliubilizatsiia Mg2+-zalezhnoï Ca2+-aktyvovanoï ATF-azy fraktsiï plazmatychnykh membran synaptosom

Mg2+-dependent Ca2+-activated ATPase (Mg2+,Ca2+-atpase, EC 3.61.4) in the fraction of synaptosome plasmatic membranes is activated with 0.05-0.08% solutions of digitonin and sodium deoxycholate. At higher concentrations of digitonin the activating effect lowers, sodium deoxycholate in the increasing concentrations inactivates the enzyme. 0.08% digitonin activates Mg2+,Ca2+-ATPase of synaptosome membranes, without demanding for its transition into solubilized state. Separation of non-active 0.08% digitonin extract from the deposit results in a decrease in the enzymatic activity of the latter and addition of the extract to the deposit activates the enzyme. At least two components separable from each other are likely to be necessary for the enzyme activity manifestation. A solubilized preparation of Mg2+,Ca2+-ATPase with the maximum activity and the ratio of total ATPase to Mg2+-ATPase equal to 3.5-4.0 may be obtained by extraction with 0.15-0.20% digitonin solution. Maximum quantily of protein is extracted by means of digitonin in the same concentrations. The extracted protein is divided in 7.5% polyacrylamide gel into eight-ten electrophoretic zones.