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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.

Abstract. 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 wholeblood viscosity in local veins.Keywords: blood viscosity, mucopolysaccharide polysulfate, rheology Mucopolysaccharide polysulfate (MPS) is a preparation of glycosaminoglycans derived from mammalian cartilage that has several structural and functional similarities to heparin (1). Since glycosaminoglycans, including MPS, reduce the incidence of thrombotic events and rebalance lipid metabolism, they have recently been proposed as a treatment for the complications of atherosclerosis (2, 3). However, because only 2 clinical studies have examined changes in blood viscosity with MPS, the in vitro effects of MPS on whole-blood viscosity (BV) are poorly understood (4,5). In the present study, we examined the dose-dependent effects of MPS on coagulation variables and BV in human blood.First, we compared the antithrombotic effects of heparin and MPS. Blood samples were drawn between 9 and 11 a.m. from a cubital vein of healthy male volunteers (aged 20 to 22 years), none of whom were obese or were smokers. Informed consent was obtained from all volunteers. Thirty microliters of heparin sodium or MPS was added to a 3-ml sample of blood and gently mixed by inversion. Heparin sodium (Aventis Pharma, Tokyo) was prepared to a final concentration of 0.5 or 2.0 IU / ml. MPS (kindly provided by Maruho, Osaka) was prepared to a final concentration 0.01% or 0.1% (w / w). As a control, normal saline was added to blood samples instead of heparin sodium or MPS. The blood sample and drugs or saline were mixed by inversion in a glass tube and then incubated at 37°C.Then 250 or 550 s after the end of incubation, the samples were citrated and subjected to blood coagulation tests. Levels of thrombin-antithrombin III complex (TAT) were measured with an enzyme immunoassay method, and levels of fibrin monomer (FM) were measured with a latex immunoassay method using a specific antibody, F405.Statistical analysis was performed with the ShirleyWilliams test to compare values in blood samples to which heparin sodium, MPS, or saline had been added. The results are presented as means ± S.D.Both 0.01% and 0.1% MPS significantly reduced FM and TAT levels in a manner similar to that of 2.0 IU / ml heparin sodium (Table 1). Furthermore, the anticoagulant effects of both 0.01% and 0.1% MPS were slightly greater than that of 0.5 IU / ml heparin sodium.Next, we examined the effects of MPS dosage on BV. A blood sample was mixed by inversion with 0.01%, 0.1%, or 1.0% MPS and then immediately poured gently into a bottle and...

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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.

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