RESUMEN
We measured whole blood viscosity to investigate the time course of the fibrinolytic activity of the recombinant tissue plasminogen activator alteplase. Changes in blood viscosity over time were determined using an oscillation-type viscometer at a shear rate of 400 to 500 per second. Blood viscosity initially increased with alteplase as in untreated blood, but then decreased, reflecting the fibrinolytic activity of generated plasmin. Blood viscosity subsequently stabilized at a level below the initial value owing to the dissolution of both fibrin and fibrinogen by alteplase. To our knowledge, the present study is the first to examine the time course of changes in BV during fibrin formation and degradation. The results indicated that the fibrinolyic agent alteplase might provide the additional benefit of increasing blood flow by lowering blood viscosity.
Asunto(s)
Viscosidad Sanguínea , Activador de Tejido Plasminógeno/metabolismo , Fibrina/metabolismo , Fibrinógeno/metabolismo , Fibrinolisina/metabolismo , Humanos , Cinética , Masculino , Proteínas Recombinantes/metabolismo , Factores de Tiempo , Activador de Tejido Plasminógeno/genéticaRESUMEN
To clarify the relationship of the intensity of acute exercise to sudden cardiac death, we examined the effects of short-term heavy and light exercise on whole blood viscosity. Nine healthy sedentary male volunteers performed ten minutes of heavy (more than 95% of maximum oxygen consumption) or light (60% to 65% of maximum oxygen consumption) exercise. Blood samples were obtained before, immediately after, and one hour after exercise. The whole blood viscosity was immediately examined with an oscillation-type viscometer and was found to increase significantly after exercise and subsequently return to baseline levels within one hour after exercise. The whole blood viscosity increased by a similar degree after heavy or light exercise. Therefore, our results suggest that there is a similar risk of sudden cardiac death, due to increased whole blood viscosity, after short-term heavy or light exercise.
Asunto(s)
Viscosidad Sanguínea , Ejercicio Físico , Adulto , Muerte Súbita Cardíaca/etiología , Electrocardiografía , Prueba de Esfuerzo , Frecuencia Cardíaca , Hematócrito , Humanos , Masculino , Consumo de OxígenoRESUMEN
We examined the dose-dependent effects of mucopolysaccharide polysulfate (MPS) on coagulation variables and whole-blood viscosity in human blood. Both 0.01% and 0.1% MPS significantly reduced levels of both fibrin monomer and thrombin-antithrombin III complex in a manner similar to that of 2.0 IU/ml heparin sodium. Furthermore, MPS dose-dependently decreased whole-blood viscosity, as measured with an oscillation viscometer. Because MPS can be applied in creams and gels, percutaneous application of MPS may effectively reduce whole-blood viscosity in local veins.
Asunto(s)
Viscosidad Sanguínea/efectos de los fármacos , Glicosaminoglicanos/farmacología , Adulto , Coagulación Sanguínea/efectos de los fármacos , Coagulación Sanguínea/fisiología , Viscosidad Sanguínea/fisiología , Relación Dosis-Respuesta a Droga , Humanos , MasculinoRESUMEN
We examined the effects on whole blood viscosity and coagulation time of various dosages of the synthetic low-molecular protease inhibitors gabexate mesilate and nafamostat mesilate with an oscillation-type viscometer. When either agent was added, blood viscosity decreased dose-dependently along a sigmoid-like curve. Furthermore, coagulation time was shorter with gabexate mesilate than with nafamostat mesilate owing to the differences of half-life in human blood. Thrombin generation, which results from the activation of coagulation factors, is inhibited by synthetic protease inhibitors and subsequently decreases blood viscosity dose-dependently.