Tag Archives: tissue-type plasminogen activator

Determination of plasminogen/plasmin system components and indicators of lipoproteins oxidative modification under arterial hypertension

O. I. Yusova1, O. V. Savchuk1, T. V. Grinenko1, O. B. Kuchmenko2, L. S. Mhitaryan2, O. H. Kupchins’ka2, I. N. Yevstratova2, O. O. Matova2, N. M. Vasilinchuk2, T. F. Drobot’ko2

 1Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: yusova07@gmail.com;
2SI NSC “Strazhesko Institute of Cardiology”, National Academy of Medical Sciences of Ukraine, Kyiv

The present study was investigated of levels of oxidative modification of lipoproteins and content of plasminogen/plasmin system components – tissue-type plasminogen activator (t-PA) and plasminogen activators inhibitor-1 (PAI-1), in patients with stage II arterial hypertension (AHT) and resistant form of AHT. It was established that t-PA level in blood plasma of the patients is 2 times lower under stage II hypertension than normal and 2.5 times lower under resistant AHT. The inhibitor activity is 1.5 and 2 times higher consequently. It is concluded that patients with AHT have a decreased fibrinolytic potential, which can cause thrombotic states. Our evaluation showed a significant accumulation of products of lipid and protein oxidation, decrease of activity of antioxidant enzymes and changes of the activity of high density-lipoproteins-associated enzymes (decrease of paraoxonase-1 activity, increase of myeloperoxidase activity). Oxidized lipoproteins, t-PA and PAI-1 can be used as prognostic markers of development of complications and for evaluating the efficacy of therapy in patients with arterial hypertension.

Ca(2+)-dependent regulation of fibrinolytic system activation on fibrin(ogen) D-domains

T. A. Yatsenko, V. M. Rybachuk, S. M. Kharchenko, T. V. Grinenko

Palladin Instiute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
e-mail: tetyanaa.yatsenko@gmail.com

In the present study, we investigated whether calcium content modulation in D-domains of fibrin(ogen) was involved in fibrinolytic process activation. To investigate the effect of Ca2+-dependent changes in D-domains two types of fibrinogen fragments D and cross-linked fibrin fragments DD were obtained from plasmin hydrolysate of human fibrin(ogen): chelator-treated and without chelating agents. The study of plasminogen activation by tissue-type plasminogen activator on D- and DD-fragments had shown the intensification of plasmin formation in case of EDTA pretreatment of fragments. The proenzyme activation rate on DD also increased in the presence of EGTA in concentration-dependent manner. Potentiating effect of EGTA-pretreated DD-fragment on plasminogen activation by tPA was decreased in the presence of Ca2+. Activation rate reduction was observed according to the increase of CaCl2 concentration in the reaction medium. The intensification of plasminogen activation potentiation by chelator-treated fibrin(ogen) D-domain containing fragments and subsequent potentiation decrease in the presence of Ca2+ indicated the requirement of Ca2+-dependent changes in D-domains for plasminogen activation sites exposure and initiation of fibrinolysis.