Decrease in whole blood viscosity in alloxan diabetic rabbits.

Whole blood and plasma viscosity of normal and alloxan diabetic rabbits were measured by means of cone in cone viscosimeters at different shear rates. Blood behaves like a non-Newtonian fluid, i.e. the viscosity is shear rate-dependent whereas plasma viscosity remains constant over the shear rate range employed, i.e. behaves like a Newtonian fluid. Blood viscosity was found to be statistically significantly decreased in the alloxan diabetic group in comparison to the control group. The decrease is attributed to a slight decrease in mean hematocrit and mean plasma viscosity of the diabetic animals. The possible mechanisms of these changes are discussed.