COMPARATIVE PLASMA VISCOSITY MEASUREMENTS IN HEALTHY-SUBJECTS

The aim of the present investigation is to evaluate the measurement of plasma viscosity, carried out by tube capillary viscometer and to com pare the results with those of the dynamic apparent viscosity, determi ned by standardized rotational viscometer. The study was carried out i n 28 clinically healthy volunteers. Gravity force capillary viscometer s of Ubbelohde type were worked out in the laboratory for the purpose of the study. Simultaneous measurement of plasma viscosity was perform ed with the rheometer LS 30 Contraves with diameters of cylinders phi( 1) = 11 mm, phi(2) = 12 mm, h = 8 mm, and the shear rates varying from 0.017 to 128.5 s(-1). All theological measurements were carried out a t 37 degrees C. Certain nonlinearity at the low shear rate range is di splayed when the plasma dynamic viscosity is measured by rotational vi scometer. The mean plasma viscosity values vary between 3.15 mPa.s at 0.0237 s(-1) to 1.34 mPa.s at 128.5 s(-1). The mean values of the dyna mic plasma viscosity, estimated by capillary viscometer are 1.34 +/- 0 .05 mPa.s. The viscosity values obtained with the capillary viscometer are slightly lower than those obtained with the Couette viscometer. T his phenomenon is probably due to surface adsorbed proteins resulting in spuriously high torque.