Effects of Shimotsu-to on the microcirculation of the bulbar conjunctiva and hemorheological parameters in normal subjects.

The effects of 'Shimotsu-to' (Si-Wu-Tang in Chinese), one of the most important prescriptions for 'ketsukyo' and 'oketsu' syndrome in traditional Chinese medicine, on the microcirculation of bulbar conjunctiva and the hemorheological parameters were examined in ten healthy volunteers. After one hour of oral administration of Shimotsu-to extract, the blood flow rate and the blood flow volume significantly increased and the DEA (maximum diameter of the column of intravascular erythrocyte aggregation) decreased. The whole blood viscosity declined at middle and high shear rates, but both the plasma viscosity and the erythrocyte deformability were not effected. These results suggest that Shimotsu-to has a salutary effect on the microcirculation through a decrease in the whole blood viscosity.