Study of the mechanism of hemostatic effect of desmopressin.

Intravenous injection of 1 microg/kg desmopressin to rabbits not only accelerated clotting of arterial blood (maximally by 59.16 +/- 8.53% after 1 h), but also increased the number of microvesicles containing the integral enzyme 5'-nucleotidase in the arterial blood from the initial level of 36.

Cell microvesicles during experimental endotoxemia.

The dynamics of microvesicle formation in arterial blood in generalized Schwartzman phenomenon was studied. Successive (with 24-h interval) intravenous injections of endotoxin to rabbits in a dose of 1 mg/kg and 3 mg/kg caused an increase in the content of microvesicles in the blood, some of them containing ecto-5'-nucleotidase. Biphasic changes in arterial blood clotting time and erythrocyte hemolysis were observed.

Effect of lupus anticoagulant on the interaction of prothrombin with platelets.

We studied binding of (125)I-labeled prothrombin to platelets in the presence of circulating endogenous lupus anticoagulant. Lupus anticoagulant modulated the interaction and increased affinity of prothrombin for calcium-independent binding sites on platelets. The number of these sites decreased, while the total number of calcium-dependent binding sites increased.

Effect of radiation on prothrombin interactions with cell membrane fragments.

Binding of (125)I-labeled prothrombin to normal and radiation-damaged (1 and 3.5 Gy) fragments of cell membranes was studied. Irradiation significantly increased adsorption capacity of cell membranes for (125)I-prothrombin.