[Analysis of dynamics of complement-dependent hemolysis].
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Animals↗
Biomedical subjects
E V Riumina
Publications and source records attributed to E V Riumina.
[Concentration-functional interrelationships in the human alternative complement activation pathway].
The dependence of the rate of human complement mediated lysis of rabbit erythrocytes on concentrations of factors B and D of the alternative pathway is characterized by saturation kinetics. At low B and D concentrations no lysis occurs until certain "threshold" concentrations of the respective factor are reached. The type of dependence of the hemolysis rates on the C3 concentration is wavelike, i.e., at definite C3 concentrations the erythrocyte lysis is inhibited. It has been supposed that C3 not only mediates the complement-dependent hemolysis but also plays a prominent role in the self-regulation of this process.
Animals↗
[Turbidimetric analysis of fibrin polymerization in the plasma].
The turbidimetrical assay of thrombin-induced plasma coagulation provides a possibility to estimate both stages of fibrinogen-fibrin conversion. The initial one, which proceeds without any change of turbidity, reflects the process of protofibril formation, and the second stage of lateral aggregation, is characterized by the rise of turbidity. The influence of heparin, alga (Laminaria digitata) aqueons extracts, and collagenase on the indices of the turbidity-time curve has been studied. It was established that the alga extracts possessed the powerful heparin-like anticoagulant activity. The both agents influenced the first stage of the turbidity-time curve, suppressing protofibril formation, which reflects the thrombin inhibition. Nevertheless, they differed in their mode of dose-dependence. While the time of protofibril formation was direct proportional to the alga extract concentration, it was rising more intensively with heparin dose elevation. Plasma pre incubation with alga extract or heparin did not influence their action. Treatment with plasma collagenase changed only the second stage of the coagulation curve. It inhibited the process of protofibril lateral aggregation in the direct proportional manner. It must be due to fibrin digestion by the enzyme. We propose that fibrin cleavage by collagenase occurred out of the thrombin action sites, because the velocity of protofibril accumulation stayed unchanged. Our data illustrate the usefulness of the turbidimetrical analysis in the studies of the agents' action mechanisms on blood coagulation, in conditions close to physiological ones.
Blood Coagulation↗
[Modification of proteolytic complement cascade after treatment with exogenous heparin].
The influence of heparin therapeutic concentrations (0.25-10 U/ml) on the kinetic indices of human serum complement activity has been studied. An acceleration of complement-dependent lysis of rabbit erythrocytes via alternative complement pathway was found at low (0.25-0.5 U/ml) heparin concentrations and complement inhibition at higher (5-10 U/ml) concentration. The alternative pathway inhibition was revealed mainly by lag-period elongation of the hemolysis. Heparin in the concentrations more then 1 U/ml caused dose-dependent lowering of sheep erythrocytes hemolysis rate accompanied with reciprocal elevation of complement hemolytical capacity, which shows more "economical" consumption of complement components at heparin presence. The identical effect was observed in sera, deficient in factor D of alternative pathway of complement activation. This can be an evidence of the prevailing heparin inhibition of the classical pathway.
Animals↗
[The action of karbogal on the complement system under model conditions and in an animal experiment].
The influence of dimethylperfluorocyclohexane (carbogal) on the hemolytic activity of human blood serum complement was studied in vitro. It has been show that different effects of carbogol on the complement depend on the serum lipid composition. Endotracheal administration of carbogal to rats results in a significant reduction of complement activity in the animal's blood. Significant changes in the hemolytic activity of the complement recorded 21 days after the endotracheal administration of the compound are, probably, associated with the complement depletion after its activation by carbogal particles or with disorders in the complement component synthesis by macrophages.
Animals↗
[The mechanisms of fucoidan action on human complement].
The action of fucoidan (a sulfated polysaccharide) on human serum complement has been under study. Fucoidan inhibited the classical pathway of complement activation up to the complete arrest of the complement-dependent hemolysis achieved at the polysaccharide concentration higher than 200-250 mg per 1 ml of human serum. The classical pathway inhibition by fucoidan seems to be due to the binding to subcomponent C1q. In the alternative pathway, fucoidan also showed an inhibitory effect seen first in dose-dependent elongation of the lag-period preceding complement-dependent hemolysis. Experimental data suggest that fucoidan target is complement factor D, some part of the which (less than 30%) remains stable to the polysaccharide concentration as high as 600 mg/ml. The fucoidan properties described in this study can be used for cell protection against self-activated complement.
Animals↗
[The effect of plasmin on complement in human blood serum].
Plasma exhibited the dose-dependent inactivating effect on human blood serum hemolytic complement both in classic and alternative pathways. Negative correlation (r = -0.8) was found between the rate of complement inactivation and content of C3 component. Plasmin appears to hydrolyze mainly the C3 component of complement as a result of which hemolytic activity of complement is decreased.
Blood↗
[Structure and properties of the complement system proteinases].
Biochemical aspects of enzymes of the complement functioning are presented. Proteolytic, esterolytic and amidolytic characteristics of the complement components which are enzymes in their nature as well as the structure and properties of complex proteases of the activated complement are analyzed.
Amides↗
[Activity of the complement system in blood serum of dogs after treatment of acute necrotic pancreatitis with boiled pancreatic juice].
The investigations were conducted on 14 dogs. To assess the blood serum complement system, the erythrocyte lytic rate of a rabbit (RE) and a sheep (SE), the hemolytic capacity of the complement system against rabbit (RH) and sheep (SH) was measured. In acute necrotic pancreatitis, no changes in SE and SH were revealed either in the control and experimental animals. RH was decreased both in the control and experimental animals. Lower RE was found only in the controls untreated with boiled pancreatic juice. It can be suggested that in the controls the decrease in the parameter RE that characterized the activity of the complement system is associated with the emergence of complement inhibitors, which did not take place when the boiled juice was given. Preventing the complement inhibitors from forming, pancreatic juice is likely to be able to diminish the body's endogenous intoxication which is a cause of death in acute necrotic pancreatitis. This may be suggested by the higher survival of the animals and lower relative extent of pancreatic acinar tissue necrosis after boiled pancreatic juice treatment of acute necrotic pancreatitis.
Animals↗